Cod sursa(job #1356684)

Utilizator sandugavrilaGavrila Alexandru sandugavrila Data 23 februarie 2015 15:38:22
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.96 kb
#include <cstdio>
#include <queue>
#include <vector>
#include <cstring>
#define NMAX 100010
using namespace std;
queue <int> q;
vector <int> v[NMAX];
bool viz[NMAX];
int len[NMAX];
int bfs(int start)
{
   // memset(len,-1,NMAX);
    q.push(start);
    len[start]=0;
    viz[start]=1;
    int x;
    while(!q.empty())
    {
        x=q.front();
        for(int i=0;i<v[x].size();i++)
            if(!viz[v[x][i]])
            {
                viz[v[x][i]]=1;
                q.push(v[x][i]);
                len[v[x][i]]=len[x]+1;
            }
        q.pop();
    }
}
int main()
{
    freopen("bfs.in","r",stdin);
    freopen("bfs.out","w",stdout);

    int n,m,s,a,b;
    scanf("%d%d%d",&n,&m,&s);
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d",&a,&b);
        v[a].push_back(b);
    }
    for(int i=1;i<=n;i++) len[i]=-1;
    bfs(s);
    for(int i=1;i<=n;i++)
        printf("%d ",len[i]);
    printf("\n");
    return 0;
}