Cod sursa(job #1452456)

Utilizator VisanCosminVisan Tudor Cosmin VisanCosmin Data 20 iunie 2015 22:29:47
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.99 kb
#include <iostream>
#include <vector>
#include <queue>
#include <stdio.h>


#define maxn 100010

using namespace std;


vector<vector<int > > a;
int n,m,start,cost[maxn];
queue<int> q;

void BFS(int st)
{
    for(int i = 0;i<maxn;i++)
        cost[i] = -1;
    cost[st] = 0;

    int aux;
    for(q.push(st);!q.empty();q.pop())
    {
        aux = q.front();
        for(int i = 0;i<a[aux].size();i++)
        {
            if(cost[a[aux][i]] == -1)
            {
                q.push(a[aux][i]);
                cost[a[aux][i]] = cost[aux]+1;
            }
        }
    }
}


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

    int x,y;

    a.reserve(maxn);
    scanf("%d%d%d",&n,&m,&start);
    for(int i = 0 ;i<m;i++)
    {
        scanf("%d%d",&x,&y);
        a[x].push_back(y);
    }

    BFS(start);

    for(int i = 1 ;i<=n;i++)
    {
        printf("%d ",cost[i]);
    }








    return 0;
}