Cod sursa(job #1132707)

Utilizator alex_bucevschiBucevschi Alexandru alex_bucevschi Data 3 martie 2014 20:37:08
Problema BFS - Parcurgere in latime Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 0.99 kb
#include <cstdio>
#include <vector>
#include <deque>
#include <cstring>
#define N 100010
using namespace std;
int n,m,X,i,j,val,viz[N],ok,a[N];
vector<int> v[N];
deque <pair<int,int> >Q;
int main()
{
    freopen("bfs.in","r",stdin);
    freopen("bfs.out","w",stdout);
    scanf("%d%d%d",&n,&m,&X);
    for(;m;m--)
    {
        scanf("%d%d",&i,&j);
        v[i].push_back(j);
    }
    Q.push_back(make_pair(X,0));
    viz[i]=1;
    for(;Q.size();)
    {
        j=Q.front().first;
        val=Q.front().second;
        Q.pop_front();
        for(vector<int>::iterator it=v[j].begin();it!=v[j].end();it++)
        {
            if(!a[*it])
               a[*it]=val+1;
            if(!viz[*it])
            {
                viz[*it]=1;
                Q.push_back(make_pair(*it,val+1));
            }
        }
    }
    for(i=1;i<=n;i++)
    {
        if(!a[i])printf("-1 ");
        else if(i==X)printf("0 ");
        else printf("%d ",a[i]);
    }
    return 0;
}