Cod sursa(job #767301)

Utilizator test_666013Testez test_666013 Data 13 iulie 2012 11:10:56
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.85 kb
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
#define MAX 100001
#define INF 0xfffffff

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

void bfs(){
    int x,y,p,u;

    for(int i=1;i<=n;i++) d[i] = INF;
    d[s] = 0;
    c[p = u = 1] = s;
    while( p <= u )
    {
        x = c[p++];
        for(int i=0;i<g[x].size();i++)
        {
            y = g[x][i];
            if( d[y] > d[x] + 1 )
            {
                d[y] = d[x] + 1;
                c[++u] = y;
            }
        }
    }
}

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] == INF && i != s ? -1 : d[i]);

    return 0;
}