Compilare: user.cpp: In function ‘int main()’: user.cpp:74:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<ans[ind].size();j++) ^ user.cpp:36:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hamster.in","r",stdin); ^ user.cpp:37:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hamster.out","w",stdout); ^ user.cpp:38:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s);ch=0; ^ user.cpp:40:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s);ch=0; ^ user.cpp:66:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s);ch=0; ^ /tmp/ccW0dZEP.o: In function `main': user.cpp:(.text.startup+0x5b): warning: the `gets' function is dangerous and should not be used.