If we are using STL program in codeblocks, we have to enable GNU c++ option
Project->Build options->Have g++ follow the coming C++ 0x ISO C++
language standard [-std =c++0x]
Otherwise it wont compile in codeblocks editor. while submitting the
same code in codeforces.com, we have to select
GNU C++0x4 option for uploading the cpp file.