Compilare: user.cpp: In function ‘void Sterge()’: user.cpp:26:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[a].size(); ++i) ^ user.cpp:32:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[b].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:53:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mvc.in","r",stdin); ^ user.cpp:54:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mvc.out","w",stdout); ^ user.cpp:55:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&N); ^ user.cpp:57:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ",&C[i]); ^ user.cpp:59:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n",&x,&y); ^