Cod sursa(job #2138837)

Utilizator Paul_BalanPavel Balan Paul_Balan Data 21 februarie 2018 21:47:16
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.78 kb
#include <bits/stdc++.h>

using namespace std;

vector<int> V[100100];
queue<int> Q;
int n,m,s,x,y,k,a[100100],b[100100];
int viz[100100];

void bfs(int p){
    Q.push(p);
    while (!Q.empty()){
        int t = Q.front();
        Q.pop();
        for (int i=0; i<V[t].size(); i++){
            if (!viz[V[t][i]] && V[t][i]!= p) Q.push(V[t][i]), viz[V[t][i]] = viz[t] + 1;
        }
    }
}

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

    fin >> n >> m >> s;

    for (int i = 1; i<=m; i++){
        fin >> x >> y;
        V[x].push_back(y);
    }

    bfs(s);

    for (int i = 1; i<=n; i++){
        if (i == s) fout << "0 ";
        else if (viz[i] == 0) fout << "-1 ";
        else fout << viz[i] << " ";
    }

    return 0;
}