Cod sursa(job #1985145)

Utilizator nicolaefilatNicolae Filat nicolaefilat Data 26 mai 2017 23:13:17
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.09 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream in("bfs.in");
ofstream out("bfs.out");
const int inf = (1 << 30);
const int maxn = 100005;
vector <int> v[maxn];
int dist[maxn];
queue <int> q;


void bfs(int nod)
{
    q.push(nod);
    for(int i = 0; i < maxn; i++)
        dist[i] = inf;
    dist[nod] = 0;
    q.push(nod);
    while(!q.empty())
    {
        int p = q.front();
        q.pop();
        for(unsigned int i = 0; i < v[i].size(); i++)
        {
            int vec = v[p][i]; // noul element
            if(dist[vec] > dist[p] + 1){
                dist[vec] = dist[p] + 1;
                q.push(vec);
            }
        }
    }

}

int main ()
{
    int n, m, s;
    in >> n >> m >> s;
    for(int i = 1; i <= m; i++)
    {
        int x, y;
        in >> x >> y;
        v[x].push_back(y);
    }
    bfs(s)
    for(int i = 1; i <= n; i++)
    {
        if(dist[i] == inf)
            out << -1;
        else
            out << dist[i];
        out << " ";
    }
    return 0;
}