Compilare: user.cpp: In function ‘int main()’: user.cpp:37:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<G[vf].size(); i++) ^ user.cpp:66:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<G[vf].size(); j++) ^ user.cpp:14:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("graf.in","r",stdin); ^ user.cpp:15:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("graf.out","w",stdout); ^ user.cpp:17:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &n,&m,&x,&y); ^ user.cpp:22:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&poz1,&poz2); ^