Compilare: user.cpp: In function ‘int main()’: user.cpp:19:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[i%3].size();j++){ ^ user.cpp:26:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<edges.size(); i++) ^ user.cpp:11:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fenrir.in", "r", stdin); ^ user.cpp:12:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("fenrir.out", "w", stdout); ^