Compilare: user.cpp: In function ‘int main()’: user.cpp:149:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (C.size() == it) ^ user.cpp:158:56: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < C.size(); ++ i) ^ user.cpp:118:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:123:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^