Compilare: user.cpp: In function ‘int main()’: user.cpp:41:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int q=1;q<=v2[v[v1[j]]].size();q++) v2[minn].push_back(v2[j][q]); ^ user.cpp:43:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int q=1;q<=v3[v[v1[j]]].size();q++) v3[minn].push_back(v3[j][q]); ^ user.cpp:52:58: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v3[a].size()>0) {for(int i=0;i<v3[a].size();i++) printf("%d ",v3[a][i]);printf("\n");a++;} ^ user.cpp:11:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("flori.in","r",stdin); ^ user.cpp:12:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("flori.out","w",stdout); ^ user.cpp:14:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^ user.cpp:20:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^