Cod sursa(job #1323189)

Utilizator gabrielvGabriel Vanca gabrielv Data 20 ianuarie 2015 19:46:11
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.04 kb
#include <iostream>
#include <vector>
#include <queue>

using namespace std;

#define NMAX 100005

int N,M,S;

int dist[NMAX];

vector < int > G[NMAX];

queue < int > Q;

void Read()
{
    freopen("bfs.in","r",stdin);
    scanf("%d%d%d",&N,&M,&S);

    for(int i=1;i<=M;i++)
    {
        int x,y;
        scanf("%d%d",&x,&y);
        G[x].push_back(y);
    }
}

void BFS()
{
    Q.push(S);

    while(!Q.empty())
    {
        int nod = Q.front();
        Q.pop();

        for(vector < int > :: iterator it = G[nod].begin(); it != G[nod].end(); it++)
        {
            if(dist[*it])
                continue;
            dist[*it] = dist[nod] + 1;
            Q.push(*it);
        }
    }
}

void Print()
{
    freopen("bfs.out","w",stdout);

    for(int i=1;i<=N;i++)
    {
        if(i==S)
            printf("0 ");
        if(dist[i])
            printf("%d ",dist[i]);
        else
            printf("-1 ");
    }
}

int main()
{
    Read();
    BFS();
    Print();
    return 0;
}