Cod sursa(job #652121)

Utilizator d.andreiDiaconeasa Andrei d.andrei Data 23 decembrie 2011 00:24:05
Problema BFS - Parcurgere in latime Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 0.84 kb
#include <cstdio>
#include <queue>
#include <vector>

using namespace std;

#define file_in "bfs.in"
#define file_out "bfs.out"

#define nmax 101010

int n,m,viz[nmax],s,cost[nmax];
vector<int> G[nmax];

void bfs(int nod){
	
	cost[nod]=0;
	queue<int> Q;
	int x;
	vector<int> :: iterator it;
	Q.push(nod);
	viz[nod]=1;
	while(!Q.empty()){
		
		x=Q.back();
		Q.pop();
		for (it=G[x].begin();it!=G[x].end();++it)
			 if (!viz[*it]){
				 viz[*it]=1;
				 cost[*it]=cost[x]+1;
				 Q.push(*it);
			 }
	}
}
		

int main(){
	
	int i,a,b;
	freopen(file_in,"r",stdin);
	freopen(file_out,"w",stdout);
	
	scanf("%d %d %d", &n, &m, &s);
	while(m--){
		
		scanf("%d %d", &a, &b);
		G[a].push_back(b);
	}
	
	for (i=1;i<=n;++i)
		 cost[i]=-1;
	
	bfs(s);
	
	for (i=1;i<=n;++i)
		 printf("%d ", cost[i]);
	
	return 0;
	
}