Compilare: user.cpp: In function ‘bool cuplare(int)’: user.cpp:27:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<vec[x].size(); i++) ^ user.cpp:36:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<vec[x].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:96:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<vec[i].size(); j++) ^ user.cpp:52:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("colorare2.in","r",stdin); ^ user.cpp:53:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("colorare2.out","w",stdout); ^