Cod sursa(job #1223504)

Utilizator TimitocArdelean Andrei Timotei Timitoc Data 28 august 2014 12:14:11
Problema BFS - Parcurgere in latime Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.2 kb
#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <queue>
#include <bitset>

using namespace std;

int n, m, s;
vector<int> vec[100005];
queue<int> q;
int viz[100005];

void citire()
{
    int x, y;
    scanf("%d %d %d", &n, &m, &s);
    for (int i = 0; i < m; i++)
    {
        scanf("%d %d", &x, &y);
        if (x != y)
            vec[x].push_back(y);
    }
}

void bfs(int dest)
{
    q.push(s);
    int nod;
    while (!q.empty())
    {
        nod = q.front();
        if (nod == dest)
            break;
        q.pop();
        for (int i = 0; i < vec[nod].size(); i++)
        {
            if (!viz[vec[nod][i]])
            {
                viz[vec[nod][i]] = viz[nod] + 1;
                q.push(vec[nod][i]);
            }
        }
    }
    if (nod == dest)
        printf("%d ", viz[nod]);
    else
        printf("-1 ");
}

int main()
{
    freopen("bfs.in", "r", stdin);
    freopen("bfs.out", "w", stdout);
    citire();
    for (int i = 1; i <= n; i++)
    {
        for (int i = 0; i <= n; i ++)
            viz[i] = 0;
        while(!q.empty())
            q.pop();
        bfs(i);
    }
    return 0;
}