Compilare: user.cpp: In function ‘int main()’: user.cpp:51:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(sol.size() > n) ^ user.cpp:18:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.in", "r", stdin); ^ user.cpp:19:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.out", "w", stdout); ^ user.cpp:21:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:24:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &b); ^