Cod sursa(job #2667730)

Utilizator oloeriudeliaOloeriu Delia Ioana oloeriudelia Data 3 noiembrie 2020 19:37:02
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.92 kb
#include <bits/stdc++.h>

using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
queue <int> q;
vector <int> v[100010];
int n, m, s, viz[100010], a, b;
void bfs(int s)
{
    q.push(s);
    while(!q.empty())
    {
        int nod=q.front();
        q.pop();
        int lg=v[nod].size()-1;
        for(int i=0; i<=lg; ++i)
        {
            int k=v[nod][i];
            if(viz[k]==0 and k!=s)
            {
                q.push(k);
                viz[k]=viz[nod]+1;
            }
        }
    }
}
int main()
{
    fin>>n>>m>>s;
    for(int i=1; i<=m; ++i)
    {
        fin>>a>>b;
        v[a].push_back(b);
    }
    bfs(s);
    for(int i=1; i<=n; ++i)
    {
        if(i==s)
            fout<<0;
        else
        {
            if(viz[i]==0)
                fout<<"-1";
            else
                fout<<viz[i];
        }
        fout<<' ';
    }
    return 0;
}