Compilare: user.cpp: In function ‘void ver(grad, int)’: user.cpp:28:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<gr.mc.size();i++) ^ user.cpp:38:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<gr.mc.size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:54:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("felinare.in","r",stdin); ^ user.cpp:55:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("felinare.out","w",stdout); ^ user.cpp:57:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:61:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^