Cod sursa(job #962406)

Utilizator teoionescuIonescu Teodor teoionescu Data 14 iunie 2013 22:15:47
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.61 kb
#include<fstream>
#include<vector>
#include<queue>
using namespace std;
ifstream in("bfs.in");
ofstream out("bfs.out");
const int N = 100005;
int n,m,s,x,y,r;
int v[N];
vector<int> G[N];
queue<int> q;
int main(){
	in>>n>>m>>s;
	for(int i=1;i<=n;i++) v[i]=-1;
	for(;m;--m){
		in>>x>>y;
		G[x].push_back(y);
	}
	q.push(s);
	v[s]=0;
	r=1;
	while(!q.empty()){
		x=q.front(); q.pop();
		for(vector<int>::iterator it = G[x].begin(); it != G[x].end(); it++){
			if(v[*it]==-1) q.push(*it);
			if(v[*it]==-1 || v[*it]>v[x]+1) v[*it]=v[x]+1;
		}
	}
	for(int i=1;i<=n;i++) out<<v[i]<<' ';
	return 0;
}