Lama-lama aku jadi mikir, sebenarnya siapa itu Tahun Baru? Padahal kalau untuk manusia, nama “Tahun Baru” kedengarannya aneh. Jadi bingung..

Tapi kalau misal dia bukan manusia, terus apa dong? Atau jangan-jangan dia makhluk luar angkasa yang datang ke bumi dan ingin menguasai dunia? Wew… O_o

Wah.. kalau itu bener berarti aku harus waspada dong. Aku harus mulai nyari beberapa orang terpilih untuk mencegah si Tahun Baru itu menguasai dunia. Mungkin aku bisa nyari orang-orang dengan kekuatan super atau nyari beberapa pendekar pedang untuk bersiaga. Tapi kok rasanya aneh kalau misalnya si Tahun Baru itu pengen menguasai dunia, kenapa orang-orang malah seneng Tahun Baru datang? walah.. jadi tambah bingung.. -_-”

Atau mungkin dia sebutir seonggok sehelai sepasang sebiji seorang superhero yang ingin membasmi segala bentuk kejahatan di muka bumi? Kalau gitu bagus dong, ga heran juga orang-orang ga sabar nunggu dia datang. Tapi kayaknya kalau gitu ga mungkin juga, emang mungkin ya membasmi segala kejahatan di bumi? kayaknya muslihat, eh mustahil deh…
Kok jadi makin bingung lagi gini ya… x_x

Ah, ga tau deh.. peduli apa.. biar Tahun Baru datang juga aku ga peduli, kenal juga nggak.. Daripada malah ntar jadi makin bingung terus akhirnya aku lari telanjang sambil geleng-geleng keliling kampus.. -_-”

Kalau mau langsung lihat sumber aslinya, klik disini aja.

Silakan dibaca, semoga berguna.

———————————————————–

Common Mistakes in Online and Real-time Contests

by Shahriar Manzoor

Introduction

Each year the Association for Computing Machinery (ACM) arranges a worldwide programming contest. This contest has two rounds: the regional contests and the World Final. The teams with the best results in the regional contests advance to the World Final. The contest showcases the best programmers in the world to representatives of large companies who are looking for talent. When practicing for programming competitions, remember that all your efforts should be directed at improving your programming skills. No matter what your performance is in a contest, don’t be disappointed. Success in programming contests is affected by factors other than skill, most importantly, adrenaline, luck, and the problem set of the contest. One way of getting immediate feedback on your efforts is to join the Valladolid Online Programming Practice/Contest or the online judge hosted by Ural State University (USU). Successfully solving problems increases your online ranking in the respective competitions.

This article is for beginning programmers who are new to programming contests. I will discuss the common problems faced in contests, the University of Valladolid online judge, and the USU online judge. The suggestions are divided into three parts: General Suggestions, Online Contest Suggestions, and Valladolid-Specific Suggestions. Throughout this paper, please note that in real-time contests, the judges are human and in online contests, the judges are computer programs, unless otherwise noted.

Different Types of Programming Contests

Many programming contests take place throughout the year, such as ACM regional contests, International Olympiad in Informatics (IOI), Centrinës Europos informatikos olimpiados (CEOI), and Programmer of the Month (POTM) contest. The most prestigious live programming contest is the ACM International Collegiate Programming Contest (ICPC), and the most prestigious online contest is the Internet Problem Solving Contest (IPSC). In this section, I will discuss some of the contests.

ACM International Collegiate Programming Contest (ICPC)

ICPC, first held in 1977, is now held yearly [4]. The contest lasts five hours and generally contains eight problems. (However, the 2001 World Finals contained nine problems.) Three person teams are allotted a single computer. The teams submit their solutions to a judging software named PC2 developed at California State University, Sacramento (CSUS). The permitted programming languages are C/C++, Pascal, and Java.

Online Contests

Online contests require no travel and are often less tense [1]. The submission rules for the online contests at the Valladolid site and the USU online judge site are the same: the contestants must mail their solutions to a certain e-mail address. The IPSC rules are quite different. The IPSC Contest Organizer provides inputs for the problems. Instead of e-mailing their solutions, the contestants have to e-mail their outputs.

Some Tips for Contestants

A good team is essential to succeeding in a programming contest. A good programming team must have knowledge of standard algorithms and the ability to find an appropriate algorithm for every problem in the set. Furthermore, teams should be able to code algorithms into a working program and work well together.

The problems presented in programming contests often fall into one of five categories including search, graph theoretic, geometric, dynamic programming, trivial, and non-standard. Search problems usually require implementing breadth-first search or depth-first search. Graph theoretic problems commonly include shortest path, maximum flow, minimum spanning tree, etc. Geometric problems are based on general and computational geometry. Dynamic programming problems are to be solved with tabular methods. Trivial problems include easy problems or problems that can be solved without much knowledge of algorithms, such as prime number related problems. Non-standard problems are those that do not fall into any of these classes, such as simulated annealing, mathematically plotting n-queens, or even problems based on research papers. To learn more about how problems are set in a contest you can read Tom Verhoeff’s paper [6].

What you should do to become a good team

There is no magic recipe to becoming a good team, however, by observing the points below (some of which were taken from Ernst et al. [3]) you can certainly improve. When training, make sure that every member of the team is proficient in the basics, such as writing procedures, debugging, and compiling. An effective team will have members with specialties so the team as a whole has expertise in search, graph traversal, dynamic programming, and mathematics. All team members should know each other’s strengths and weaknesses and communicate effectively with each other. This is important, for deciding which member should solve each problem. Always think about the welfare of the team. Solving problems together can also be helpful. This strategy works when the problem set is hard. This strategy is also good for teams whose aim is to solve one problem very well. On the other hand, the most efficient way to write a program is to write it alone, avoiding extraneous communication and the confusion caused by different programming styles.

As in all competitions, training under circumstances similar to contests is helpful. During the contest make sure you read all the problems and categorize them into easy, medium and hard. Tackling the easiest problems first is usually a good idea. If possible try to view the current standings and find out which problem is being solved the most. If that problem has not yet been solved by your team, try to solve it immediately, odds are it is an easy problem to solve. Furthermore, if the your solution to the easiest problem in the contest is rejected for careless mistakes, it is often a good idea to have another member redo the problem. When the judges reject your solution, try to think about your mistakes before trying to debug. Real-time debugging is the ultimate sin, you don’t waste too much of your time with a single problem. In a five-hour contest you have 15 person-hours and five computer-hours. Thus, computer-hours are extremely valuable. Try not to let the computer sit idle. One way to keep the computer active is to use the chair in front of the computer only for typing and not for thinking. You can also save computer time by writing your program on paper, analyzing it, and then use the computer. Lastly, it is important to remember that the scoring system of a contest is digital. You do not get any points for a 99%-solved problem. At the end of the contest you may find that you have solved all the problems 90%, and your team is at the bottom of the rank list.

Different Types of Judge Responses

The following are the different types of judge replies that you can encounter in a contest [2]:

Correct

Your program must read input from a file or standard input according to the specification of the contest question. Judges will test your program with their secret input. If your program’s output matches the judges’ output you will be judged correct.

Incorrect output

If the output of your program does not match what the judges expect, you will get an incorrect output notification. Generally, incorrect output occurs because you have either misunderstood the problem, missed a trick in the question, didn’t check the extreme conditions or simply are not experienced enough to solve the problem. Problems often contain tricks that are missed by not reading the problem statement very carefully.

No output

Your program does not produce an output. Generally this occurs because of a misinterpretation of the input format, or file. For example, there might be a mixup in the input filename e.g., the judge is giving input from “a.in,” but your program is reading input from “b.in.” It is also possible that the path specified in your program for the input file is incorrect. The input file is in most cases in the current directory. Errors often occurs because of poor variable type selection or because a runtime error has occurred, but the judge failed to detect it.

Presentation error

Presentation error’s occur when your program produces correct output for the judges’ secret data but does not produce it in the correct format. Presentation error is discussed in detail later in this article.

Runtime error

This error indicates that your program performs an illegal operation when run on judges’ input. Some illegal operations include invalid memory references such as accessing outside an array boundary. There are also a number of common mathematical errors such as divide by zero error, overflow or domain error.

Time limit exceeded

In a contest, the judge has a specified time limit for every problem. When your program does not terminate in that specified time limit you get this error. It is possible that you are using an inefficient algorithm, e.g., trying to find the factorial of a large number recursively, or perhaps that you have a bug in your program producing an infinite loop. One common error is for your program to wait for input from the standard input device when the judge is expecting you to take input from files. A related error comes from assuming wrong input data format, e.g., you assume that input will be terminated with a “#” symbol while the judge input terminates with end-of-file.

General Suggestions for Contests

Maximum memory

The maximum memory allowed on the Valladolid site is 32MB. This includes memory for global variables, the heap, and the stack. Even if you find that you have allocated much less than 64K memory, you will find that the judge often shows that more memory has been allocated. Also, you should not allocate 32 MB of global memory because 32MB is maximum for all types of memory. The maximum memory for real contests varies; for the World Final, it is greater than 128MB.

Problems with DOS Compilers and memory allocation

Many of us like to use DOS compilers like Turbo C++ 3.0 and Borland C++, which do not support allocating more than 64K memory at a time. It is always a good idea to allocate memory with a constant so that your test runs use less than 64K memory. Before the submit run, the size of memory can be increased by just changing the value of the constant. If you don’t practice this, it is very likely that you will face problems like “Run time error,” “Time limit exceeded,” and “Wrong answer.” An example:

int const SIZE=100;
int store[SIZE][SIZE];
void initialize(void)
{
	int   i,j;
	for  (i=0;i<SIZE;i++)
			for  (j=0;j<SIZE;j++)
			   store[i][j]=0;
}

“Time limit exceeded” is not always “Time limit exceeded”

When you submit a program to the judge, the judge gives you a response, but this response is not always accurate. For example, if you allocate less memory than is required, the program may not terminate (it may not even crash), and the judge will tell you “Time limit exceeded.” On seeing this message, if you try to optimize your program rather than correcting the memory allocation problem, your program will never be accepted. The following example illustrates this problem. The skeleton of your program is as follows:

#include <stdio.h>
int const MAX=100;
int array[MAX],I;
void main (void)
{
	for (i=0; i<=100; i++)
	{
		if (array[i]==100)
		{
			array[i] = -10000;
			- - - - - -
			- - - - - -
			- - - - - -
		}
	}
}

In this example, you have allocated a 100 element array. Your program attempts to access array element 100, which is out of the range [0..99], because of an error in the for loop statement. It will instead access the address of counter variable i. Because the value array[100] is set to 10000, the counter value will be set to 10000, so your loop will take a much longer time to terminate and may not even complete at all. So, the judge will give you message “Time limit exceeded” even though it actually is a memory allocation error.

Test the program with multiple datasets

There is always a sample input and output provided with each contest question. Inexperienced contestants get excited when one of their programs matches the sample output for the corresponding input, and they think that the problem has been solved. So they submit the problem for judgment without further testing and, in many cases, find they have the wrong answer. Testing only one set of data does not check if the variables of the program are properly initialized because by default all global variables have the value zero (integers = 0, chars = ‘\x0′, floats= 0.0 and pointers = NULL). Even if you use multiple datasets the error may remain untraced if the input datasets are all the same size, in some cases descending in size or ascending in size. So, the size of the dataset sequence should be random. It is always a good idea to write a separate function for initialization.

Take the input of floats in arrays

Consider the following program segment

#include<stdio.h>
float store[100];
void main (void)
{
	int j;
	for (j=0;j<100;j++)
		scanf( "%f", &store[j]); 

	scanf("%f", &store[j]);

t linked.” To get rid of this type of error, just change it to take the input
into a normal floating point variable then assign that variable to the array,
as follows:

#include <stdio.h>
float store[100];
void main (void)
{
	int j;
	float temp;
	for (j=0;j<100;j++)
	{
		scanf(   "%f"  ,&temp);
		store[j]=temp;
	}
}

Mark Dettinger’s suggestions on geometric problems

Mark Dettinger was the coach for the team from the University of Ulm. He suggested to me that sometimes it is a good idea to avoid geometric problems unless one has prewritten routines. The routines that can be useful are:

Judging the judge!

Judges often omit information. For example, judges in my country give the error “Time limit exceeded” but never say what the time limit is. In Valladolid, often the input size is not specified (e.g., problem 497-Strategic defense initiative).

Suppose that the maximum number of inputs is not given. This is often vital information because if the number is small, you can use backtracking, and if it is large, you have to use techniques like dynamic programming or backtracking with memorization. In problem 497, the maximum possible number of missiles to intercept is not given. Suppose that the loop for(j=0;j<100000000;j++) takes one second to run for the judge, and an unknown N is the number of inputs given by the online judge. Send the following program with your code. Place it just after you have read the value of N.

for  (I=1;I<=20;I++)
{
	if  (I*1000>=N)
	{
		for(j=0;j<I*100000000;j++);
	}
}

From the runtime of the program you will know the number of input N. Using this method you can also determine how fast the judge’s computer is compared with yours and thus find out the approximate time limit for any problem on your computer. Most of the live contests have a practice session prior to the contest. On this day you should try to determine the speed of the judge computer by sending programs consisting of many loops and nested loops.

Did you know that there was a mistake in a problem of the World Final 2000? The culprit problem was Problem F. The problem specification said that the input graph would be complete but not all inputs by the judge were complete graphs. At least one of the teams sent a program that checked if the input graph was complete. If the input graph was incomplete, then their program entered an infinite loop. So, the response from the judge was “Time limit exceeded.” From this response they were able to know that some of the input graphs were incomplete and solved the problem accordingly.

Use double instead of float

It is always a good idea to use double instead of float because double gives higher precision and range. Always remember that there is also a data type called a long double. In Unix/Linux C/C++, there is also a long long integer. Sometimes it is specified in the problem statement to use float type. In those cases, use floats.

Advanced use of printf() and scanf()

Those who have forgotten the advanced use of printf() and scanf(), recall the following examples:

scanf("%[ABCDEFGHIJKLMNOPQRSTUVWXYZ]", &line);  //line is a string

This scanf() function takes only uppercase letters as input to line and any other characters other than A..Z terminates the string. Similarly the following scanf() will behave like gets():

scanf("%[^\n]", line);  //line is a string

Learn the default terminating characters for scanf(). Try to read all the advanced features of scanf() and printf(). This will help you in the long run.

Using new line with scanf()

If the content of a file (input.txt) is
abc
def

and the following program is executed to take input from the file:

char input[100], ch;
void main (void)
{
	freopen("input.txt", "rb", stdin);
	scanf("%s", &input);
	scanf("%c", &ch);
}

What will be the value of input and ch?

The following is a slight modification to the code:

char input[100], ch;
void main (void)
{
	freopen("input.txt", "rb", stdin);
	scanf("%s\n", &input);
	scanf("%c", &ch);
}

What will be their value now? The value of ch will be ‘\n’ for the first code and ‘d’ for the second code.

Memorize the value of pi

You should always try to remember the value of pi as far as possible, 3.1415926535897932384626433832795, certainly the part in italics. The judges may not give the value in the question, and if you use values like 22/7 or 3.1416 or 3.142857, then it is very likely that some of the critical judge inputs will cause you to get the wrong answer. You can also get the value of pi as a compiler-defined constant or from the following code: Pi=2*acos(0)

Problems with equality of floating point (double or float) numbers

You cannot always check the equality of floating point numbers with the = = operator in C/C++. Logically their values may be same, but due to precision limit and rounding errors they may differ by some small amount and may be incorrectly deemed unequal by your program. So, to check the equality of two floating point numbers a and b, you may use codes like:

if (fabs(a-b)<ERROR) printf("They are equal\n");

Here, ERROR is a very small floating-point value like 1e-15. Actually, 1e-15 is the default value that the judge solution writers normally use. This value may change if the precision is specified in the problem statement.

The cunning judges

Judges always try to make easy problem statements longer to make them look harder and the difficult problem statements shorter to make them look easy. For example, a problem statement can be “Find the common area of two polygons” — the statement is simple, but the solution is very difficult. Another example is “For a given number find two such equal numbers whose multiplication result will be equal to the given number.” Though the second statement is much longer than the first, the second problem statement is only asking to find the square root of a number, which can be done using a built-in function.

Use the assert function

It is always nice to use the C/C++ assert() function, which is in the header file assert.h. With the assert() function you can check for a predefined value for a variable or an expression at a certain stage of your program. If for some reason the variable or expression does not have the specified value, assert() will print an error message. See your C/C++ documentation for further details.

Avoid recursion

It is almost always a good idea to avoid recursion in programming contests. Recursion takes more time, recursive programs crash more frequently especially in the case of parsing, and, for some people, recursion is harder to debug. But recursion should not be discounted completely, as some problems are very easy to solve recursively (DFS, backtracking), and there are some people who like to think recursively. However, it is a bad habit to solve problems recursively if they can be easily solved iteratively. In live programming contests, there is no point in writing classic code, or code that is compact but often hard to understand and debug. In programming contests, classic code serves only to illustrate the brilliance of the programmer. For example, the code for swapping two values can be written classically as:

#define swap(xxx, yyy) (xxx) ^= (yyy) ^= (xxx) ^= (yyy)

But in a contest you will not get extra points for this type of code writing.

Improve your understanding of probability and card games

Having a good understanding of probability is vital to being a good programmer. If you want to measure your grasp of probability, just solve problem 556 of Valladolid and go through a statistics book on probability. Know about probability theorems, independent and dependent events, and heads/tails probability. You should also be able to solve common card game-related problems.

Be careful about using gets() and scanf() together

You should also be careful about using gets() and scanf() in the same program. Test it with the following scenario. The code is:

scanf("%s\n", &dummy);
gets(name);

And the input file is:

ABCDEF
bbbbbXXX

What do you get as the value of name? “XXX” or “bbbbbXXX” (Here, “b” means blank or space)

Suggestions for UNIX-based Online Judges and Contests

Function portability

Not all C/C++ functions available in DOS are available in UNIX. Check the documentation for the portability among operating systems. If a function is portable to UNIX, you can use it to solve problems on the Valladolid and USU sites. Use only standard input and output functions for taking inputs and producing outputs.

itoa(), the important function that UNIX doesn’t have

UNIX does not support the important function itoa(), which converts an integer to a string. The replacement for this function can be:

char numstr[100];
int num=1200;
sprintf(numstr, "%d", num);  //to decimal
sprintf(numstr, "%X", num);  //to uppercase hexadecimal

Try to find replacements for other functions that are not available in UNIX/LINUX.

Problems with the settings of mailer program

Some problems don’t get accepted even if they are solved correctly. Such problems from Valladolid are 371- Ackermann Function, 336-A node too far, 466-mirror, mirror, etc. It is because our e-mail programs (e.g., Outlook Express, Eudora) break longer lines, and these problems have long lines in their output. So in Outlook Express you should go to Tools-> Options-> Send-> Send text setting and change the Automatically Wrap Text from 76 (default) to 132. Similar options can be found in other mailer programs. The Ural State University online judge has a program submission form with which you can directly submit your program without sending an e-mail. Remember that problems with mailer settings can cause both wrong answers and compile errors.

Presentation error

Presentation errors are neither caused by algorithmic nor logical mistakes. There is a difference between the presentation error of online judges and that of live judges. The latter are able to detect mistakes such as misspellings, extra words, extra spaces, etc., and differentiate them from algorithmic errors, such as wrong cost, wrong decisions, etc. These mistakes are the presentation errors as graded by the human judges. On the other hand, online judges in most cases compare the judge output and the contestant output with the help of a file compare program so that even spelling mistakes can cause a “wrong answer.” Generally, when the file compare program finds extra new lines, these are considered to be presentation error. Human judges, though, do not typically detect these mistakes. But now computers are becoming more powerful, larger judge inputs are being used and larger output files are being generated. In live contests, special judge programs are being used that can detect presentation errors, multiple correct solutions, etc. We are advancing towards better judging methods and better programming skills. The recent statistics of the ACM shows that participation in the ACM International Collegiate Programming Contest is increasing dramatically, and in the near future the competition in programming contests will be more intense [5]. So the improvement of the judging system is almost a necessity.

A common mistake of contestants

Recently, I arranged several contests with Rezaul Alam Chowdhury and in collaboration with the University of Valladolid and have seen contestants make careless mistakes. The most prominent mistake is taking things for granted. In a problem I specified that the inputs will be integers (as defined in mathematics) but did not specify the range of input and many contestants assumed that the range will be 0->(2^32-1). But in reality many large numbers were given as input. The maximum input file size was specified from which one could assume what was the maximum possible number. There were also some negative numbers in the input because integers can be negative.

The causes of compile error

Compile error is a common error on the Valladolid site. It may seem annoying to compile and run a program, then send it to the online judge and get a compile error. Generally these errors occur because contestants omitted #include files. Some compilers do not require including the header files even when we use functions under those header files. However, the online judge never allows this. For example, some functions exist both in math.h and stdlib.h. For the online judge, you need to include both of the header files if you want to use them. Compiler errors also occur commonly when contestants do not specify the correct language. Often C code implemented in some compilers inadvertently takes advantage of C++ features. When the language specified to the judge is C, a compile error is generated. For example, the following may be compiled as a C program in a DOS/Windows environment but not in UNIX/LINUX.

for (int i=0; i<100; i++)
{
	printf("Compile Error\n");
}

E-mail sending format

Mail sent to the online judge should be in plain text format. If the mail is in Rich Text or HTML, the program will not compile. You should not send your program as an attachment.

Mysterious characters

When I first started programming for Valladolid, I used Turbo C++. After a program was successfully completed, I opened the source code in Notepad, selected the whole text, copied and pasted it in my mail editor, and sent the program to the Valladolid site. I got a Compile error message but could not discover the cause. One day, I pasted it in my email editor, saved it as a text file, and then opened it in my DOS text editor. I discovered some mysterious characters in the file, which were invisible in Windows. If you receive a Compile error message and cannot discover the cause, check if your mail or text editor is adding extra symbols to your code.

Using non-portable functions

Compile errors are caused by the use of the functions which are only available in DOS and not in LINUX, such as strrev(), itoa() etc.

Using C++ style comments

C++ allows a comment style that starts with //. If the mailer wraps a comment to two lines, you may get a compile error.

Valladolid-specific suggestions

The next section provides suggestions for solving problems for the Valladolid online judge.
Types of input in the Valladolid online judge
There are four types of input in the online judge. (Latest change)
Non-multiple input without special correction program (Red Flag)
Non-multiple input with special correction program (Orange Flag)
Multiple input without special correction program (Blue Flag)
Multiple input with special correction program (Green Flag)

What is a special correction Program?

There are some problems that have one unique output for a single input, and other problems with multiple output for the same input. For example if you are asked to find the maximum appearing string of length 3 in the string “abcabcabcijkijkijk,” unfortunately the answer can be both “abc” and “ijk.” So, if your program gives the output “abc,” it is correct, “ijk” is also correct. The judge program cannot determine the correctness of your program by simply comparing your output to the judge program output. The judge must write a special program, which will read your answer and determine if it is right or wrong. This special program is described as a special correction program in the Valladolid online judge. For the problems with special correction programs, (Problem 104, 120, 135, etc., or the problems with orange || green flag), you cannot be sure that your program is incorrect even if your program output does not match the sample output for the given sample input.

“Multiple input programs” are an invention of the online judge. The online judge often uses the problems and data that were first presented in live contests. Many solutions to problems presented in live contests take a single set of data, give the output for it, and terminate. This does not imply that the judges will give only a single set of data. The judges actually give multiple files as input one after another and compare the corresponding output files with the judge output. However, the Valladolid online judge gives only one file as input. It inserts all the judge inputs into a single file and at the top of that file, it writes how many sets of inputs there are. This number is the same as the number of input files the contest judges used. A blank line now separates each set of data. So the structure of the input file for multiple input program becomes:

Integer N //denoting the number of sets of input
–blank line—
input set 1 //As described in the problem statement
–blank line—
input set 2 //As described in the problem statement
–blank line—
input set 3 //As described in the problem statement
–blank line—
.
.
.
–blank line—
input set n //As described in the problem statement
–end of file–

Note that there should be no blank after the last set of data. Sometimes there may be, so always check. The structure of the output file for a multiple input program becomes:

Output for set 1 //As described in the problem statement
–Blank line—
Output for set 2 //As described in the problem statement
–Blank line—
Output for set 3 //As described in the problem statement
–Blank line—
.
.
.
–blank line—
Output for set n //As described in the problem statement
–end of file–

The USU online judge does not have multiple input programs like Valladolid. It prefers to give multiple files as input and sets a time limit for each set of input.

Problems of multiple input programs

There are some issues that you should consider differently for multiple input programs. Even if the input specification says that the input terminates with the end of file (EOF), each set of input is actually terminated by a blank line, except for the last one, which is terminated by the end of file. Also, be careful about the initialization of variables. If they are not properly initialized, your program may work for a single set of data but give correct output for multiple sets of data. All global variables are initialized to their corresponding zeros. Thus, for a single set of input, the initialization may not be necessary, but for multiple inputs, it is a must.

The Fixing Mistake section

Always be sure to see the Fixing Mistake section of the Valladolid online judge. Some of the problems in the Valladolid online judge have errors, which are corrected on this page.

Read the message board

Always try to read the message board of the Valladolid site. You will learn many things from other programmers. The USU online judge also has a message board. You can also submit your own views and problems via these boards.

Conclusion

Many people believe that the best programmer is the one with greatest knowledge of algorithms. However, problem-solving skills contribute to programming success as much as raw knowledge of algorithms. Don’t lose your nerve during a contest, and always try to perform your best.

References
1Astrachan, O., V. Khera, and D. Kotz. The Internet Programming Contest: A Report and Philosophy
2Chowdhury, R. A., and S. Manzoor. Orientation: National Computer Programming Contest 2000, Bangladesh National Programming Contest, 2000.
3Ernst, F., J. Moelands, and S. Pieterse. Teamwork in Programming Contests: 3 * 1 = 4, Crossroads, 3.2.
4Kaykobad, M. Bangladeshi Students in the ACM ICPC and World Championships, Computer Weekly.
5Poucher, W. B. ACM-ICPC 2001, RCD Remarks, RCD Meeting of World Finals 2001.
6Verhoeff, T. Guidelines for Producing a Programming-Contest Problem Set: http://wwwpa.win.tue.nl/wstomv/publications/guidelines.html

Useful Links

ACM Home Page: http://www.acm.org/
ACM International Collegiate Programming Contest Problem Set Archive: http://www.acm.inf.ethz.ch/ProblemSetArchive.html
ACM International Collegiate Programming Contest Web page: http://acm.baylor.edu/acmicpc/
American Computer Science League (ACSL) Homepage: http://www.acsl.org/acsl/
Centrinës Europos informatikos olimpiados (CEOI) Resource Page: http://aldona.mii.lt/pms/olimp/tarpt/ceoi.html
Informatics Competitions Link Page: http://olympiads.win.tue.nl/ioi/misc/other.html
Internet Problem Solving Contest (IPSC) web page: http://ipsc.ksp.sk/
International Olympiad in Informatics (IOI) web page: http://olympiads.win.tue.nl/ioi/index.html
Mark Dettinger’s Home Page: http://www.informatik.uni-ulm.de/pm/mitarbeiter/mark/
New POTM Master’s Home Page: http://contest.uvarov.ru/
PC2 Home Page: http://www.ecs.csus.edu/pc2/
POTM Master’s Home Page: http://members.tripod.com/~POTM/fah_home.html
Ural State University (USU) Problem Set Archive with Online Judge System: http://acm.timus.ru
University Waterloo Contest Page: http://plg.uwaterloo.ca/~acm00/
Valladolid 24-hour Online Judge : http://acm.uva.es/problemset
Valladolid Online Contest Hosting System: http://acm.uva.es/contest
Valladolid Problems link: 104, 120, 135, 371, 336, 466, 497.

Biography

Shahriar Manzoor (shahriar@neksus.com) is a BSc student of Bangladesh University of Engineering & Technology (BUET). He participated in the 1999 ACM Regional Contest in Dhaka, and his team was ranked third. He is a very successful contest organizer. He has arranged six online contests for the Valladolid online judge including the “World Final Warm-up Contest.” His research interests are contests, algorithms, and Web-based applications.

Acknowledgements

Shahriar Manzoor is grateful to Prof. Miguel A. Revilla for letting him arrange online contests and to Prof. William B. Poucher for asking people to participate in the World Final Warm-up Contest. He is also grateful to Ciriaco Garcia, Antonio Sanchez, F. P. Najera Cano, Fu Zhaohui, Dr. M. Kaykobad, Rezaul Alam Chowdhury, Munirul Abedin, Tanbir Ahmed, Reuber Guerra and above all his family.

Copyright 2009, The Association for Computing Machinery, Inc.
———————————————————————-

Balik lagi ke masalah blog, sebenernya sempat kepikiran buat ngisi blog ini sama jawaban tugas-tugasku, trus mungkin hasil codingan soal-soal problem solving apa gitu atau mungkin jalan algoritmanya, dari UVa OJ kek, TopCoder kek, soal dari dosen kek, atau apalah pokoknya itu.. Tapi tiba-tiba niat itu musnah..
Aku ngrasa kalau untuk posting hasil codingan gitu aku masih belum pantas, codinganku masih terlalu buruk untuk ditampilkan ke umum, haha. Trus kalau tentang posting jawaban tugas.. aduh.. gimana ya.. tugas yang mana yang mau diposting? aku kan jarang ngerjakan tugas, haha.. (-_-”). Kalau jawaban tugas, iya kalau bener, lha kalau salah? Lagian aku juga kadang ngrasa ‘belum cukup ilmu’ kalau mau posting begituan.
Tapi sebenernya, alasan utamanya bukan itu. Alasan yang paling mendasar adalah tidak adanya sebuah kerja sinkron antara otak, hasrat, dan jari untuk menuangkan semua itu menjadi sebuah bentuk hasil ketikan yang dapat di posting, yang didasari atas sebuah perasaan tidak ada keinginan untuk menggerakkan jari-jari di atas keyboard agar mampu menghasilkan tulisan-tulisan seperti yang diinginkan di atas. Biar kalimat sebelum ini sepertinya panjang, tapi kalau udah bisa menyimpulkan pasti cuman tertuju pada satu kata aja, yaitu malas. -_-”

Tapi (nah, tapi lagi..), sebenernya ada pendapat juga yang bilang kalau posting algoritma atau jawaban tugas itu kan untuk menyebarkan ilmu, jadi gapapa biar masih belum benar-benar ahli, yang penting aku memang ngerti tentang yang aku posting itu. Trus, ntar kalau misal ada pendapat lain tentang yang dibahas itu, aku juga bisa tahu, jadi ilmuku juga bisa nambah. Hemm.. pendapat itu bisa dijadikan acuan juga, mungkin suatu saat aku bisa posting tentang ilmu yang aku dapat selama ini, bisa tentang algoritma, tugas-tugas kuliah, atau apa aja, bahkan mungkin ilmu tentang menghilangkan stres kuliah dengan cara lari keliling kampus sambil gendong anak singa. Ah, tapi rasanya ga ada ilmu seperti itu.. -_-”

Awalnya aku ga yakin jadi mau ikut SRM itu ato ga, soalnya waktu ngerjakan COCI otakku rasanya mati, ga mau disuruh kerja. Aku cuma bisa submit dua soal pertama dari enam soal yang ada, padahal dua soal pertama (atau biasanya tiga) itu “soal bonus”.
Di soal ketiga, aku ga ketemu-ketemu algoritmanya, ga tau kenapa, dan aku paling lama stuck di nomer itu. Soal-soal nomer empat sampai enam lebih mudah dipahami, walaupun kalo aku bikin kodingan-nya, mungkin bisa kena limit, hehehe. Dan sialnya lagi, aku ga fullscore di soal kedua.. aarrgghh…

Setelah mengalami masa suram di COCI akhirnya aku meyakinkan diri untuk jadi ikut SRM hanya dengan pertimbangan “sudah terlanjur register” (-_-”) sambil chat sedikit-sedikit ama Risan buat nanyakan “sekarang harus ngapain?” ato “kalo udah gini, terus gimana?”, soalnya dia udah lebih berpengalaman di TopCoder daripada aku, hehe…

Hari Minggu, 8 Februari 2009 pukul 00.00….. SRM 434 dimulai… jreeenggg… (-_-”)
Di sini aku masuk di divisi II, soalnya masih unrated. Kemudian masuk ke “coding phase”, dan mulai buka soal 250pt (soal easy) dengan harapan soal yang keluar ga ada vector ato string-nya (aku masih belum menguasai vector dan string, haha). Lalu, jreengg.. soalnya terlihat cukup mudah.

Inti soal tersebut (LeastMajorityMultiple) adalah mencari sebuah bilangan terkecil yang bisa dibagi dengan sedikitnya tiga dari lima bilangan yang diinputkan (untuk lebih jelasnya, klik disini). Aku langsung kepikiran cara termudah, yaitu iterasi dari bilangan terkecil yang diinputkan sampai ketemu bilangan yang bisa dibagi tiga bilangan itu.

kode-ku waktu itu kira-kira seperti ini :

#include <string>
#include <vector>
#include <algorithm>
class LeastMajorityMultiple {
	public:int leastMajorityMultiple(int a, int b, int c, int d, int e) {

		int x, Count=0, Min;
		bool ketemu = false; 

		Min = min(a,min(b,min(c,min(d,e)))); 

		for (x=Min; !ketemu; x++) {
			Count=0;

			if (x%a==0) Count++;
			if (x%b==0) Count++;
			if (x%c==0) Count++;
			if (x%d==0) Count++;
			if (x%e==0) Count++; 

			if (Count >= 3) ketemu = true;
		} 

		x=x-1; 

		return x;
	};
}

Sebenernya kode di atas masih bisa dipersingkat, tapi waktu SRM aku mikirnya gitu dan cepet-cepet aja aku submit. Awalnya, aku sempat agak jengkel gara-gara kena’ compile error terus (aku lupa di bagian mana), soalnya aku juga masih agak bingung dengan sistem di TopCoder yang beda ama kontes lain (misal, USACO ato COCI). Tapi akhirnya, aku berhasil submit untuk 220.19pt (yang seharusnya bisa lebih baik.. T_T).
Setelah itu, aku coba buka soal 500pt (soal medium). Kalo yang ini, aku butuh kira-kira 50 menit untuk memahami soal itu, dan ternyata di 10 menit terakhir aku sadar kalo soal itu “tidak sesusah yang aku pikirkan”. Tapi mau gimana lagi, mau bikin kode-nya udah ga sempet.

Setelah selesai “coding phase” dengan 220.19pt dan menempati urutan 432 se-divisi (bukan suatu hal yang pantas dibanggakan, haha), aku tanya ke Risan, “trus, skarang ngapain, San?”, trus dia jawab, “nunggu challenge phase”. Di “challenge phase” ini, kode kita bisa dibaca oleh peserta lain, dan peserta itu bisa melakukan sebuah “challenge” dengan nyoba untuk running program kita dengan testcase dari peserta itu. Kalo program kita ngeluarkan output yang salah, program kita akan bernilai 0, dan peserta itu mendapat tambahan 50pt. Tapi kalo output yang dikeluarkan bener, peserta itu dikurangi 25pt, dan kita ga nambah apa-apa.
Peserta cuma boleh melakukan “challenge” ke lawan se-room-nya. O iya, untuk yang mungkin belum tau, di TopCoder ini kontestan dipecah jadi dua divisi berdasarkan ratingnya, yaitu Divisi I (lebih tinggi) dan Divisi II. Terus, tiap-tiap divisi dibagi jadi beberapa “room”, dan tiap room diisi sekitar sepuluh peserta lebih (aku lupa tepatnya).

Waktu “challenge phase” ini, di saat peserta lain yang se-room mungkin sibuk membaca kode lawannya, aku sibuk memandangi chat area sambil berharap ga ada yang buka kode-ku.. haha…
Setelah 15 menit “challenge phase” berlalu, aku agak lega, walaupun ada dua orang yang sempet buka kode-ku, tapi mereka ga “challenge” programku itu.. fiuhh.. =D

Habis itu, aku tanya Risan lagi denga pertanyaan yang sama, trus dia jawab “ga ngapa2in, nunggu system testingnya selesai”. Di “system testing phase” ini, program kita akan dites oleh server TopCoder dengan testcase yang mungkin jauh lebih “gila” dari yang ada di contoh input-output. Sambil chatting dikit-dikit ama Risan, aku baru tau dari dia kalo ternyata ada aturan kalo misal program kita salah di satu testcase aja, nilainya jadi 0. Waaa,, aku langsung kaget dan takut jangan-jangan kode-ku itu nanti bisa kena’ time limit…. T_T. Tapi, setelah kode-ku dibaca sebentar ama Risan, dia bilang kalo kode-ku ini ga mungkin salah dan ga mungkin kena’ limit, soalnya paling besar cuman njalankan 1000000000 iterasi dengan peningkatan secara linear, dan itu masih cukup. Wew, aku lega, soalnya aku yang masih amatiran ini masih belum terlalu memikirkan running time program waktu lagi ngoding, dan masih belum paham betul gimana cara tau apa programku masih ada dibatas limit, hehehe… =P

Dan ternyata yang dibilang Risan bener, kodeku berhasil melewati “system testing phase” dengan baik, dan di final score, aku tetep dapet 220.19pt, tapi urutanku naik jadi 386 se-divisi, hahhaa…
Setelah itu aku chatting ama Risan sambil deg-degan nunggu rating pertama.. Dan mungkin rasanya mirip waktu deg-degan nunggu pengumuman UAN (halah,, berlebihan… -_-”)
Akhirnya, ada pemberitahuan dari Topcoder kalo ratingku udah di-update, tapi aku harus logoff dulu dan login lagi untuk ngeliatnya.

Dan jreeengg… ratingku jadi 1187..!! Handle-ku ganti warna jadi ijo..!! (padahal dikit lagi 1200 dan bisa jadi biru.. -_-”). Lumayan lah menurutku yang baru pertama ikut ini, soalnya ada juga yang udah berkali-kali ikut tapi ratingnya belum ijo, ato paling ga belum nyampe 1187.. haha.. (lagi-lagi bukan hal yang pantas dibanggakan.. -_-”). Walaupun banyak juga orang yang handle-nya langsung jadi biru ato bahkan kuning waktu pertama kali ikut kontes.
FYI, urutan warna handle di TopCoder dari yang terburuk sampe terbagus adalah putih (unrated), abu-abu, hijau, biru, kuning, merah.

Sekedar tau aja bagi yang mungkin belum tau (ya kalo udah tau ga perlu diberitau… haha..), di TopCoder ini, rating seseorang bisa naik ato turun tergantung performa orang tersebut di tiap kontes, jadi bukan berarti semakin banyak ikut kontes, semakin tinggi rating.
Dan masih ada kemungkinan ratingku akan turun, tapi semoga aja ratingku bisa meningkat terus… Amiinnn

NB : Buat yang mungkin belum tau tentang TopCoder, coba klik disini, ato klik salah satu tulisan “TopCoder” di atas.

Dari situs tersebut, deskripsi dari hasil tesku :

INTPs are logical, individualistic, reserved, and very curious individuals. They focus on ideas, theories and the explanation of how things work. They are especially adept at discussions and debate. They have the ability to focus intently on a subject. They appreciate and respect intelligence in others.

Menurut situs itu lagi, tipe INTP ini sama seperti beberapa orang tersohor di dunia, seperti Albert Einstein, Blaise Pascal, Charles Darwin, dan Abraham Lincoln.

Sebenernya, aku dulu pernah ngisi juga, cuman hasilnya dapet INFP-”The Dreamer”. Beda ama yang sekarang cuman di bagian “F” dan “T”, dimana “F” di sana artinya “Feeling” dan “T” artinya “Thinking”. Sempat mikir kok bisa beda? Ato mungkin sekarang aku lebih bisa pake logika dan fakta, daripada hanya sekedar pake perasaan? Ga tau deh, haha..
Soalnya, kalo menurut situs itu, beda dari “Thinking” dan “Feeling” adalah :

Thinking people are objective and make decisions based on facts. They are ruled by their head instead of their heart. Thinking people judge situations and others based on logic.

Feeling people are subjective and make decisions based on principles and values. They are ruled by their heart instead of their head. Feeling people judge situations and others based on feelings and extenuating circumstances.

Entahlah, yang bener yang mana.. Tapi kalo menurut aku, aku lebih puas dengan hasil yang INTP daripada INFP, hehehe..

–

Ini hasil lengkap tesku :

Seminggu sebelum demo, kami baru mulai ngerjakan. Seperti anak muda kebanyakan, waktu ngerjakan, kami ga bisa serius, mesti bercanda terus (biar gak stress sih). Malah nonton video-nya MoyMoyPalaboy, dan berencana bikin video yang kaya’ gitu… (jahh.. -_-”).
Seminggu itu juga ga full ngerjakan FP PT, soalnya satu hari kepotong ada UAS fisika, trus ada UAS PTI+ngerjakan tambahannya. Total waktu bersih ngerjakan cuman empat hari..

Bodohnya, aku salah strategi ngerjakan. Masing-masing anak, aku bagi buat ngerjakan bagian-bagian program, awalnya itu kirain bikin lebih cepet jadi, tapi malah bikin bingung. O iya, aku yang bagi tugasnya, soalnya ama teman-teman disuruh jadi project manager (wah, salah pilih mereka.. haha). Waktu mau gabungkan bagian-bagian program, kami malah bingung, soalnya tiap anak pake variabel-variabel beda, fungsi beda, header beda, dan banyak yang beda lagi. Akhirnya, waktu deadline ngumpulkan, belum ada program penuh hasil gabungan kami, tapi kami udah punya satu yang seenggaknya bisa masuk ke game-nya, walaupun itu juga masih sedikit..

Waktu demo… jreengg… tet teretet tet teettt… des dess… -_-”
Kelompokku cuman demo sedikit dari yang sebenarnya udah kami kerjakan.. T_T
Bahkan asisten-asisten yang awalnya kelihatan antusias waktu liat opening, langsung seakan-akan bilang “Lhealah.. ngene thok..” (Lhealah,, cuman gini..) waktu lihat program utamanya.. hahaa…
Di program kami yang itu, belum ada tambahan-tambahan dari asisten penguji proposal, padahal udah ada beberapa yang kami bikin, seperti adjust volume, cheat, ganti karakter, save-load sampai tiga slot… ya seenggaknya walaupun cuman empat, tapi bukan tidak sama sekali.. hehehe.. maksa..

Kalo dinilai antara 0-100%, programku yang ini mungkin baru jadi sekitar 17-23%..
FP paling gagal diantara dua FP lain.. T_T
Rencana sih aku pengen nglanjutkan game ini sampe 100%, tapi masih mikir lagi.. enaknya nglanjutkan ini ato bikin baru lagi ya..?
Soalnya kan ntar kalo aku nglanjutkan game tadi, aku seenggaknya harus melibatkan kelompokku, kalo bikin baru lagi kan bisa terserah aku… Tapi rugi juga kalo game ini ga dilanjutkan… ga tau deh.. haha

Tapi ya sudahlah, kode sudah menjadi program (maksudnya niru “nasi sudah menjadi bubur”, tapi maksa.. -_-”). Semua itu dijadikan pengalaman aja. Yang penting sekarang udah libuuurrr… hahhaaa… asseeekkk…

==========>>><<<==========

Wew, akhirnya berakhir juga trilogi FP ini.
Terima kasih bagi yang udah membuang waktunya demi membaca trilogi FP ini. "The FP Trilogy" aku tulis dalam waktu sesingkat-singkatnya tanpa banyak berpikir sambil menikmati secangkir kopi hangat dan memetik enam senar kesayangan, jadi mohon maaf kalo kurang menarik.
Sekian, terima kasih.

-_-"

Wew, jangan harap enkriptor-nya bisa pakai algoritma rumit sampe orang-orang susah nebak. Enkriptor kami cuman bisa nambah kurang, itu aja maksimal nambah ato kurang antara nol sampe tiga, dan untuk input-outputnya kami pakai empat bilangan heksadesimal.
Untuk pengerjaan software atau simulasi-nya, butuh waktu bersih kira-kira setengah sampai satu jam. Aku bilangnya waktu bersih, soalnya kami benernya ga ngerjakan cuman satu jam trus selesai. Tiap kali bikin satu bagian, kira-kira 5-15 menit, langsung main “PES 2008″, ato maen “Spore™” ato kalo ga ya maen “The World of Goo”, ato maen apalah.. seadanya.. wahahaha..
Antara maen ama ngerjakannya lebih banyak maennya.. heheh

Trus kalo software-nya udah selesai, kami mesti ngerancang rangkaian simulasi tadi jadi rangkaian yang sebenarnya, pakai IC, kabel, dll.. Tapi kami pakai breadboard, jadi ga perlu pakai solder, hehehe…
Hardware-nya kami buat dalam waktu tiga hari. Sebenernya dua hari, tapi hari pertama cuman dibuat untuk nyari komponen-komponen yang dibutuhkan, hehe.. Waktu ngerjakan hardware, kami sedikit lebih serius daripada waktu ngerjakan software, soalnya selain waktunya mepet, butuh ketelitian juga buat ngerangkai komponennya ke breadboard.
Beh, FP ini yang butuh dana paling besar. Kami sekelompok aja habis sekitar 550rb buat beli komponennya.. T_T

Waktu hari-H demo hardware (Jumat, 2 Januari) punya kami belum jadi, karena belum ada input-outputnya, terpaksa kena revisi.
Revisinya Senin, 5 Januari. Habis UAS sisdig jam 7.30 sampe 9.30, aku pulang sebentar trus jam 2 ke kos temen buat ngambil rangkaiannya tadi, trus berangkat ke TC (singkatan untuk jurusan Teknik Informatika di ITS) untuk demo lagi ke asisten.
Demo kedua lebih santai, soanya yang nguji cuman satu asisten, asisten pembimbing lagi.. hahhaa.. Rangkaianku yang sebenernya belum sempurna, kata asistennya udah gitu aja, katanya yang penting rangkaiannya sudah dipasang semua dan ada outputnya, walaupun ga sesuai di simulasi.
O iya, kelupaan, software untuk simulasi rangkaian yang kami pakai adalah Multisim.

Yaa itu tadi FP sisdig… kalo antara 0-100%, rangkaianku kira-kira mencapai 80-85% selesai, tapi itu udah ditambah waktu revisi.
Kalo yang ini ga mungkin diupload, soalnya ga tau caranya upload breadboard lewat internet.. haha…

FP yang pertama itu FP PTI.. membuat game RPG dengan RPGMakerVX

Jadi, untuk mata kuliah.. (woozoozz.. MATA KULIAH!! bukan MATA PELAJARAN!! apalagi MATA KAKI.. ato MATA DADU.. tapi memang masih lebih bagus MATA UANG… halah.. -_-”). Kembali lagi ke pokok permasalahan, untuk mata kuliah PTI (Pengantar Teknologi Informasi) tiap kelompok disuruh bikin satu project bebas. Nah, kelompokku akhirnya nentukan untuk bikin game RPG pakai software RPGMakerVX, dan Alhamdulillah disetujui ama dosennya.
Awal-awal waktu disetujui, kami semangat banget, langsung cari waktu untuk kumpul dan ngerjakan project itu. Tapi alhasil, waktu kumpul yang dikerjakan malah “Counter Strike”, “Spore™”, “PES 2008″, “PES 2009″, dan lain lain…. hahhaa.. namanya juga anak muda…
Waktu untuk mengerjakan project ini cukup lama. Kalo dihitung dari awal dikasih ada satu bulan lebih, tapi kami baru ngerjakan (lebih tepatnya, benar-benar niat) waktu satu bulan kurang menjelang UAS.. hehehe…

Alhamdulillah, waktu UAS game-nya udah jadi walaupun masih ada sedikit bug dan menurut kami kurang sempurna (itu bisa dibilang udah jadi kan? hahaa). Jadwal demo kami yang seharusnya hari Jumat tanggal 9 Januari, diundur jadi hari Senin tanggal 12 Januari.
Demo berjalan lancar, dosennya cuman nanyakan masing-masing anak bikin bagian apa, trus dicoba disitu buat buktikan ke dosennya. Selesai demo, dosennya bilang “Ini punya kalian bagus, tapi kurang user manualnya. Kalau mau, saya bisa kasih nilai maksimal tapi kalian harus buat user manualnya”. Wah, kami langsung setuju aja, orang tinggal ngetik sebentar user manualnya langsung jadi. hehehe..

Yaa… itu tadi FP pertama, hasilnya kira-kira udah 93-98%…
Rencananya, aku mau upload game itu, tapi masih mau disempurnakan lagi n ditambah-tambahi ama kelompokku, jadi ditunda aja.. hehehe…

Ga tau lagi apa yang bisa ditulis. Semua kenangan tersimpan begitu rapi di otakku, namun terkadang susah untuk menuangkannya ke dalam huruf-huruf dan menjadikannya sebuah kalimat (wozooozz.. kata-kataku..entahlah, anggep aja tadi yang ngetik bukan aku.. haha). Semoga semua yang terjadi bisa membawaku jadi lebih baik.. Amin..

Trus… skarang udah masuk 2009, aku ga perlu ngucapkan selamat taun baru lagi, soalnya sekarang udah taun lama (taun baru kan cuman 1 Januari… -_-”)
=> Semoga IPS-ku dua semester bisa seenggaknya “baik sekali”..
=> Semoga bisa lolos ke babak final penyisihan ICPC tingkat nasional..
=> Pengen bikin game pake C + library Allegro, tapi masih belum tau mau bikin apa..
=> Pengen masuk MIT (wahahah… yang ini cuman ngayal, ga dibaca juga gapapa… wakaka)..
=> Pengen kumpul ama teman-teman SMA lagi…
Belum tau apalagi yang mau dituliskan.. pokoknya aku pengen semua jadi lebih baik.. AMIN..

^_^

======>>><< Semoga ntar aku bisa lulus SMA dengan nilai UNAS yang bisa bikin aku tersenyum lebar…>>> Alhamdulillah lulus, dan nilainya cukup bisa bikin tersenyum, meskipun tidak lebar
=> Bisa keterima di universitas yang aku pengen (sebenernya pengen NTU (bwahahahaha..), tapi karna itu cuman harapan kosong (alias cuman dalam khayalan), ya ITS aja deh.. wekekekeke…), n keterima di jurusan favoritku (Tek. Informatika)…>>> Alhamdulillah diterima di Tek.Informatika ITS
=> Bisa ketemu sama temen2 OSN 2007 lagi…>>> Yang dari Jatim, ketemu lima anak (Alifiyan – Komputer; Fa’ul, Satriya – Matematika; Hilman – Kimia; Mahfud – Fisika)

Akhirnya, penantianku ini berbuah hasil juga . Penantian yang bagiku lama, walaupun hanya satu bulan, sampai bikin aku kacau, hidupku terasa kurang bergairah.
Dia pun kembali membawa sebuah kebahagiaan. Gimana mau gak bahagia, lha waktu dia datang, katanya bulan ini gratis dan aku punya jatah waktu 2 hari (29 & 30 November), buat “menghabisi”-nya.

Tapi bingung juga ya.. Harus nghabiskan kuota Speedy 1 GB dalam waktu 2 hari, weleh-weleh.
Tapi aku akan berusaha.. demi kemajuan bangsa.. (halah… -_-”)