Compilare: main.cpp: In function 'int main()': main.cpp:58:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < cord[i].size(); ++j) ~~^~~~~~~~~~~~~~~~ main.cpp:25:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("trampoline.in", "r", stdin); ^ main.cpp:26:43: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("trampoline.out", "w", stdout); ^