Compilare: user.cpp: In function ‘void Sort()’: user.cpp:17:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0; j < G[Q[i]].size();j++){ ^ user.cpp: In function ‘int main()’: user.cpp:25:13: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(in); ^ user.cpp:26:14: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(out); ^ user.cpp:27:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:29:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^