Compilare: user.cpp: In function ‘int solve(int)’: user.cpp:21:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<c.size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:48:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(p.second.size()>maxi0) ^ user.cpp:54:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(p.second.size()==maxi0) ^ user.cpp:61:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<m[ans0].size();i++) ^ user.cpp:31:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pluton.in","r",stdin); ^ user.cpp:32:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pluton.out","w",stdout); ^ user.cpp:34:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ",&N); ^ user.cpp:39:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&d); ^