Compilare: user.cpp: In function ‘int main()’: user.cpp:53:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0;j<h[i].size();++j) ^ user.cpp:40:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pali.in","r",stdin); ^ user.cpp:41:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pali.out","w",stdout); ^ user.cpp:43:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s", (s+1));n=strlen(s+1); ^