Cod sursa(job #356262)

Utilizator cosmin79Carabet Cosmin Andrei cosmin79 Data 13 octombrie 2009 23:08:47
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.78 kb
#include <stdio.h>
#include <vector>
#include <queue>
#define N 1<<17
using namespace std;
int n,m,s,cost[N];
vector <int> v[N];
void read()
{
	scanf("%d%d%d",&n,&m,&s);
	int i,x,y;
	for (i=1; i<=n; i++)
		cost[i]=N;
	for (i=1; i<=m; i++)
	{
		scanf("%d%d",&x,&y);
		v[x].push_back(y);
	}
}
void solve()
{
	queue <int> Q;
	cost[s]=0;
	Q.push(s);
	int i,x;
	while (!Q.empty())
	{
		x=Q.front();
		Q.pop();
		for (i=0; i<v[x].size(); i++)
		{
			if (cost[x]+1<cost[v[x][i]])
			{
				cost[v[x][i]]=cost[x]+1;
				Q.push(v[x][i]);
			}
		}
	}
}
void show()
{
	int i;
	for (i=1; i<=n; i++)
		printf("%d ",cost[i]==N ? -1 : cost[i]);
}
int main()
{
	freopen("bfs.in","r",stdin);
	freopen("bfs.out","w",stdout);
	read();
	solve();
	show();
	return 0;
}