Cod sursa(job #1712916)

Utilizator ionalexandru98Alexandru Dumitru Ion ionalexandru98 Data 4 iunie 2016 09:52:09
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.82 kb
#include <iostream>
#include <vector>
#include <fstream>
using namespace std;
ifstream in("bfs.in");
ofstream out("bfs.out");

const int N=100001;
int n , m , S;
bool viz[N];
vector <int> a[N];
int pred[N] , q[N] , d[N];

void bfs(int x)
{
    int p,u,i;

    for(i=1;i<=n;i++)
        d[i]=-1;

    p=u=0;

    q[u++]=S;
    d[S]=0;
    pred[S]=0;

    while(p<u)
    {

        x = q[p++];
        for(i = 0 ; i<a[x].size() ; i++)
        {
            int y = a[x][i];
            if(d[y] == -1)
            {
                q[u++] = y;
                d[y] = 1+d[x];
                pred[y] = x;
            }
        }
    }

}

int main()
{
    int x , y , i;
    in>>n>>m>>S;
    for(i=1;i<=m;i++)
    {
        in>>x>>y;
        a[x].push_back(y);
    }

    bfs(S);

    for(i=1;i<=n;i++)
        out<<d[i]<<" ";
    return 0;