Compilare: user.cpp: In function ‘int pos(int)’: user.cpp:19:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < m[k].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:27:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hashuri.in","r",stdin); ^ user.cpp:28:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hashuri.out","w",stdout); ^ user.cpp:29:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:31:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &op, &x); ^