Compilare: user.cpp: In function ‘int main()’: user.cpp:35:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int it=0;it<G[k].size();it++) v[++cnt]=G[k][it]; ^ user.cpp:38:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<aux.size();i++) v[++cnt]=aux[i]; ^ user.cpp:11:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("radixsort.in","r",stdin); ^ user.cpp:12:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("radixsort.out","w",stdout); ^ user.cpp:16:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&a,&b,&c); ^