Cod sursa(job #2640862)

Utilizator HermioneMatei Hermina-Maria Hermione Data 8 august 2020 17:37:43
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.82 kb
#include <bits/stdc++.h>

using namespace std;

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

vector<vector<int>> G;
vector<int> viz;
int n;

void read(int &s)
{
    int x, y;
    f>>n>>x>>s;

    G.resize(n+1);
    viz.resize(n+1);

    while(f>>x>>y)
        G[x].push_back(y);
}

void bfs(int s)
{
    queue<int> q;
    viz[s]=1;
    q.push(s);

    while(q.size())
    {
        int y=q.front();
        q.pop();
        for(auto a:G[y])
            if(!viz[a])
            {
                viz[a]=viz[y]+1;
                q.push(a);
            }

    }
    for(int i=1; i<=n; i++)
        if(viz[i]==0)
            g<<-1<<' ';
        else
            g<<viz[i]-1<<' ';
}

int main()
{
    int s;
    read(s);
    bfs(s);
    f.close();
    g.close();

    return 0;
}