OJ Board

I sloved the problem already!

I got the error since I used the member fuction of vector .at()
the system didnt like that:)

thank you Yan anyway!:)

The compiler couldn't compile your ANSI C/C++ or GNU Pascal/Java program.

[Notes: - Select C, C++, JAVA or PASCAL in the @JUDGE_ID field, to ensure that
I'll use the proper compiler. Place a 'program...' sentence in Pascal.
Note that entry point in Java is a 'main' function in a 'Main' class ...