Compilare: user.cpp: In function ‘int main()’: user.cpp:27:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v.size(); i++) ^ user.cpp:34:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v.size(); i++) ^ user.cpp:15:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ben.in", "r", stdin); ^ user.cpp:16:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ben.out", "w", stdout); ^ user.cpp:19:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:21:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); ^