Cod sursa(job #1917118)

Utilizator B_RazvanBaboiu Razvan B_Razvan Data 9 martie 2017 11:13:27
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.03 kb
#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#define NMAX 100005

using namespace std;

int n, m, start, viz[NMAX], nrArce[NMAX];
vector <int> g[NMAX];
vector <int>::iterator it;
queue <int> q;

void read()
{
    scanf("%d%d%d", &n, &m, &start);
    int x, y;
    for(int i=1; i<=m; ++i)
    {
        scanf("%d%d", &x, &y);
        g[x].push_back(y);
    }
    for(int i=1; i<=n; ++i)
        nrArce[i]=-1;
}

void bfs()
{
    q.push(start);
    viz[start]=1;
    nrArce[start]=0;
    int nod;
    while(!q.empty())
    {
        nod=q.front();
        q.pop();
        for(it=g[nod].begin(); it!=g[nod].end(); ++it)
            if(viz[*it]==0)
            {
                viz[*it]=1;
                nrArce[*it]=nrArce[nod]+1;
                q.push(*it);
            }
    }
}

int main()
{
    freopen("bfs.in", "r", stdin);
    freopen("bfs.out", "w", stdout);
    read();
    bfs();
    for(int i=1; i<=n; ++i)
        printf("%d ", nrArce[i]);
    return 0;
}