Inspired by CHelper and JHelper, I wrote small script designed for easy use of prewritten code with C++.

It removes all comments and expands all includes with filenames wrraped with ".

You can download it here https://github.com/zakharvoit/libparser.

Usage. For example let's write some file ~/lib/binpow.h

#ifndef LIB_BINPOW_H
#define LIB_BINPOW_H
int binpow(int a, int n)
{
    int res = 1;
    while (n > 0) {
	if (n & 1) {
	    res *= a;
	}
	a *= a;
	n >>= 1;
    }
    return res;
}
#endif

And ~/contest/main.cpp

#include <iostream>
#include "binpow.h"

using namespace std;

int main()
{
    cout << binpow(2, 10) << endl;
}

Use script: ./libparser.pl ~/lib main.cpp output.cpp

Now output.cpp contains ready to submit code.

To execute this script you need perl interpreter (it should be already installed on any unix-like system). Not sure that it works on windows. If it does not work, please, write a comment.