Compilare: user.cpp: In function ‘bool is_good(int)’: user.cpp:21:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if( h[ s[i] ].size() < f ) return 0; ^ user.cpp: In function ‘int main()’: user.cpp:29:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ratina.in","r",stdin); ^ user.cpp:30:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ratina.out","w",stdout); ^ user.cpp:34:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n",&N,&M); ^ user.cpp:37:28: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(t,VMax,stdin); ^ user.cpp:51:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&K); ^ user.cpp:52:50: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(j = 1; j <= K; ++j) scanf("%d",&s[j]); ^