Compilare: user.cpp: In function ‘bool is()’: user.cpp:23:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < h[a].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:29:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("abc2.in","r",stdin); ^ user.cpp:30:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("abc2.out","w",stdout); ^ user.cpp:34:24: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s,NMax,stdin); ^ user.cpp:32:13: warning: ‘T’ may be used uninitialized in this function [-Wmaybe-uninitialized] int i,N,T,pwrP,pwrQ; ^