Compilare: user.cpp: In function ‘int main()’: user.cpp:31:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (item.second.size() > max) { ^ user.cpp:35:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] } else if (item.second.size() == max) ^ user.cpp:14:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pluton.in", "r", stdin); ^ user.cpp:15:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pluton.out", "w", stdout); ^ user.cpp:17:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:20:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("\n%s", cod); ^