Cod sursa(job #2928951)

Utilizator k20ySabaceag Marius k20y Data 24 octombrie 2022 12:16:59
Problema BFS - Parcurgere in latime Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.89 kb
#include <bits/stdc++.h>
using namespace std;

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

const int N=1e5;

int n;
vector<int> la[N];
bool parcurs[N];
int pasi[N];

void bfs(int start)
{
    queue<pair<int,int> >q;
    q.push(make_pair(start,0));
    parcurs[start]=1;

    while(!q.empty())
    {
        int nod=q.front().first;
        int nr=q.front().second;
        pasi[nod]=nr;
        for(int i=0;i<la[nod].size();i++)
        if(!parcurs[la[nod][i]])
        {
            parcurs[la[nod][i]]=1;
            q.push(make_pair(la[nod][i],nr+1));
        }

        q.pop();
    }
}
int main()
{
    int m,sursa; in>>n>>m>>sursa;

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

        la[x].push_back(y);
    }


    bfs(sursa);

    for(int i=1;i<=n;i++)
        if(!pasi[i] && i != sursa) cout<<-1<<' ';
    else out<<pasi[i]<<' ';
}