Cod sursa(job #975080)

Utilizator andrettiAndretti Naiden andretti Data 19 iulie 2013 00:09:19
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.05 kb
#include<stdio.h>
#include<vector>
#include<queue>
#define pb push_back
#define maxn 100005
#define inf 0x3f3f3f3f
using namespace std;

int n,m,s;
int v[maxn],d[maxn];
vector <int> l[maxn];

void read()
{
    int i;
    int x,y;
    scanf("%d%d%d",&n,&m,&s);
    for(i=1;i<=m;i++)
    {
        scanf("%d%d",&x,&y);
        l[x].pb(y);
    }
    for(i=1;i<=n;i++) d[i]=inf;
}

void bfs()
{
    queue <int> q;
    int k;

    q.push(s); v[s]=1; d[s]=0;
    while(!q.empty())
    {
        k=q.front();
        for(unsigned int i=0;i<l[k].size();i++)
         if(v[l[k][i]]==0)
         {
             q.push(l[k][i]);
             d[l[k][i]]=d[k]+1;
             v[l[k][i]]=1;
         }
        q.pop();
    }
}

void print()
{
    int i;
    for(i=1;i<=n;i++)
     if(d[i]==inf)
      printf("-1 ");
      else printf("%d ",d[i]);
}

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

    read();
    bfs();
    print();

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