Cod sursa(job #2926057)

Utilizator ancaoxoxSfia Anca ancaoxox Data 16 octombrie 2022 19:44:42
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.89 kb
#include <iostream>
#include <vector>
#include <queue>
#include <fstream>
#define NMAX 100005

using namespace std;

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

vector <int>v[NMAX];
queue <int>pq;

bool viz[NMAX];
int n, m, s, dist[NMAX];

void bfs(int x)
{
    pq.pop();

    for (int i=0; i<v[x].size(); i++)
        {

        if (viz[v[x][i]]==0)
        {pq.push(v[x][i]);
        viz[v[x][i]]=1;
        dist[v[x][i]]=dist[x]+1;}

        }
}


int main()
{
    int a, b;
    f >> n >> m >> s;
    for (int i=1; i<=m; i++)
    {
        f >> a >> b;
        v[a].push_back(b);
    }

    dist[s]=0;
    viz[s]=1;
    pq.push(s);


    while (!pq.empty())
            bfs(pq.front());



    for (int i=1; i<=n; i++)
        if (viz[i]==1)
            g << dist[i] << " ";
        else
            g << -1 << " ";





    return 0;
}