Cod sursa(job #1778184)

Utilizator moise_alexandruMoise Alexandru moise_alexandru Data 13 octombrie 2016 16:35:29
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.04 kb
#include <algorithm>
#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)
{
    while(!q.empty())
    {
        int p = q.front();
        q.pop();
        for(auto it : v[p])
        {
            if(dist[it] > dist[p] + 1)
            {
                q.push(it);
                dist[it] = dist[p] + 1;
            }
        }
    }
}

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);
        //v[y].push_back(x);
    }
    fill(dist + 0, dist + maxn - 1, inf);
    dist[s] = 0;
    q.push(s);
    bfs(s);
    for(int i = 1; i <= n; i++)
    {
        if(dist[i] == inf)
            out << -1;
        else
            out << dist[i];
        out << " ";
    }
    return 0;
}