Compilare: main.cpp: In function 'int main()': main.cpp:2:240: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] using namespace std;ifstream f("bfs.in");ofstream g("bfs.out");vector<int> L[100001];int v[100001],c[100001],i,n,p,u,s,x,y,m;int main(){f>>n>>m>>s;for(i=1;i<=m;i++){f>>x>>y;L[x].push_back(y);}c[1]=s;v[s]=1;p=1;u=1;while(p<=u){for(int i=0;i<L[c[p]].size();i++)if(v[L[c[p]][i]]==0){u++;c[u]=L[c[p]][i];v[L[c[p]][i]]=v[c[p]]+1;}p++;}for(i=1;i<=n;i++)g<<v[i]-1<<' ';return 0;} ~^~~~~~~~~~~~~~~