Compilare: user.cpp: In function ‘int main()’: user.cpp:19:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<sol.size();i++) { ^ user.cpp:24:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0;j<fru[l].size();j++) ^ user.cpp:31:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0;j<frr[l].size();j++) ^ user.cpp:10:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zeul.in","r",stdin); ^ user.cpp:11:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zeul.out","w",stdout); ^ user.cpp:12:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:14:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^