Cod sursa(job #759153)

Utilizator test13test13 test13 Data 16 iunie 2012 22:23:37
Problema BFS - Parcurgere in latime Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 0.8 kb
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
#define MAX 100001

vector<int>g[MAX];
int n,s,d[MAX],c[MAX];
bool viz[MAX];

void bfs(){
    int p,u,x,y;
    c[p=u=1]=s;
    viz[s]=1;
    while(p<=u)
    {
        x=c[p];
        for(int i=0;i<g[x].size();i++)
        {
            y=g[x][i];
            if(!viz[y])
            {
                viz[y]=1;
                c[u++]=y;
                d[y]=d[x]+1;
            }
        }
        p++;
    }
}

int main(){
    int m,x,y;
    freopen("bfs.in","r",stdin);
    freopen("bfs.out","w",stdout);
        scanf("%d %d %d",&n,&m,&s);
        while(m--)
        {
            scanf("%d %d",&x,&y);
            g[x].push_back(y);
        }
    bfs();
        for(int i=1;i<=n;i++)printf("%d ",d[i]==0 && i!=s ?-1:d[i]);
    return 0;
}