Compilare: user.cpp: In function ‘int main()’: user.cpp:60:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<ans.size(); ++i) ^ user.cpp:41:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cumpanit.in", "r", stdin); ^ user.cpp:42:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cumpanit.out", "w", stdout); ^ user.cpp:45:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld", &a, &b); ^