Compilare: user.cpp: In function ‘int main()’: user.cpp:89:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < ans [0].size (); ++ i) ^ user.cpp:92:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < ans [1].size (); ++ i) ^ user.cpp:25:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("zaharel.in", "r", stdin); ^ user.cpp:26:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("zaharel.out", "w", stdout); ^ user.cpp:28:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &u, &m); ^ user.cpp:30:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d %c", &x, &y, &type); ^