Compilare: main.cpp: In function 'int main()': main.cpp:64:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < ord[i].size(); ++j) ~~^~~~~~~~~~~~~~~ main.cpp:39:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("stv.in", "r", stdin); ^ main.cpp:40:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("stv.out", "w", stdout); ^