Cod sursa(job #2369664)

Utilizator SineMineSzasz Bogdan SineMine Data 6 martie 2019 08:43:38
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.03 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;

ifstream fin("bfs.in");
ofstream fout("bfs.out");

int n, m, s;                      ///nr noduri, muchii si inceput
vector <int> g[100001];           ///matrice de adiacenta

void read()
{
    fin>>n>>m>>s;
    for(int i=1; i<=m; i++){
        int x, y;
        fin>>x>>y;
        g[x].push_back(y);
    }
}

int cost[100001];
queue <int> q;

void BFS(int nod)
{
    for(int i = 1; i <= n; ++i)
        cost[i] = -1;
    cost[nod] = 0;

    q.push(nod);
    for(int i = 1; !q.empty(); i++){
        for(int j = 0; j < g[q.front()].size(); ++j)
            {
                if(cost[g[q.front()][j]]==-1)
                {
                    q.push(g[q.front()][j] );
                    cost[g[q.front()][j]] = cost[q.front()] + 1;
                }
            }
        q.pop();
    }
}

int main()
{
    read();
    BFS(s);
    for(int i=1; i<=n; i++)
        fout<<cost[i]<<' ';
}