Cod sursa(job #2715974)

Utilizator TigoanMateiTigoan Matei-Daniel TigoanMatei Data 4 martie 2021 14:34:11
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.97 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <climits>
#include <queue>

using namespace std;

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

int n, m, x, y, s;
int comps;

bool viz[100005];
int dist[100005];

vector <int> G[100005];

void bfs(int nod)
{
    queue <int> Q;
    int top;

    for(int i = 1; i <= n; ++ i) dist[i] = INT_MAX;
    dist[nod] = 0;

    Q.push(nod);

    while(!Q.empty())
    {
        top = Q.front();

        Q.pop();

        for(auto v : G[top])
            if(dist[v] > dist[top] + 1)
            {
                dist[v] = dist[top] + 1;
                Q.push(v);
            }
    }
}

int main()
{
    in >> n >> m >> s;
    for(int i = 1; i <= m; ++ i)
    {
        in >> x >> y;

        G[x].push_back(y);
    }

    bfs(s);

    for(int i = 1; i <= n; ++ i)
        if(dist[i] == INT_MAX && i != s) out << "-1 ";
        else out << dist[i] << " ";
    return 0;
}