Cod sursa(job #2667681)

Utilizator oloeriudeliaOloeriu Delia Ioana oloeriudelia Data 3 noiembrie 2020 18:54:16
Problema BFS - Parcurgere in latime Scor 30
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.88 kb
#include <bits/stdc++.h>

using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
queue <int> q;
vector <int> v[100002];
int n, m, s, viz[100002], a, b;
void bfs(int s)
{
    q.push(s);
    while(!q.empty())
    {
        int nod=q.front();
        q.pop();
        for(int i=0;i<=v[nod].size()-1;++i)
        {
            if(viz[v[nod][i]]==0 and v[nod][i]!=s)
            {
                q.push(v[nod][i]);
                viz[v[nod][i]]=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;
}