Cod sursa(job #476478)

Utilizator doru.nituNitu Doru Constantin doru.nitu Data 11 august 2010 10:37:34
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.9 kb
#include<cstdio>
#include<queue>
#include<vector>
#include<bitset>

using namespace std;

int i,n,m,d[100100],s;

bitset<100010> fol;
vector<int> a[100010];
queue<int> q;

int main()
{
    freopen("bfs.in","r",stdin);
    freopen("bfs.out","w",stdout);

    scanf("%d%d%d",&n,&m,&s);

    fol[s]=1;
    q.push(s);

    for(i=1;i<=m;++i)
    {
        int x,y;
        scanf("%d%d",&x,&y);
        a[x].push_back(y);
    }

    while(!q.empty())
    {
        int u=q.front();
        q.pop();

        for(i=0;i<a[u].size();++i)
            if(!fol[ a[u][i] ])
            {
                fol[a[u][i]]=1;
                q.push(a[u][i]);
                d[ a[u][i] ]= d[u]+1;
            }
    }

    for(i=1;i<=n;++i)
        if(d[i]==0&&i!=s) printf("-1 ");
        else printf("%d ",d[i]);
    printf("\n");

    fclose(stdin);
    fclose(stdout);
    return 0;
}