Cod sursa(job #1989155)

Utilizator MaligMamaliga cu smantana Malig Data 6 iunie 2017 09:14:37
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.97 kb
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <vector>
#include <queue>

using namespace std;
ifstream in("bfs.in");
ofstream out("bfs.out");

#define ll long long
#define pb push_back
const int NMax = 1e5 + 5;
const int inf = 1e9 + 5;

int N,M,S;
int dist[NMax];
vector<int> v[NMax];

int main() {
    in>>N>>M>>S;
    while (M--) {
        int a,b;
        in>>a>>b;

        v[a].pb(b);
    }

    for (int i=1;i <= N;++i) {
        dist[i] = inf;
    }
    dist[S] = 0;

    queue<int> Q;
    Q.push(S);
    while (Q.size()) {
        int node = Q.front();
        Q.pop();

        for (auto nxt : v[node]) {
            if (dist[nxt] != inf) {
                continue;
            }

            dist[nxt] = dist[node] + 1;
            Q.push(nxt);
        }
    }

    for (int i=1;i <= N;++i) {
        out<<( (dist[i] == inf) ? -1 : dist[i] )<<' ';
    }

    in.close();out.close();
    return 0;
}