Cod sursa(job #2686028)

Utilizator AndreiDeltaBalanici Andrei Daniel AndreiDelta Data 18 decembrie 2020 13:08:19
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.97 kb
#include <bits/stdc++.h>
#define pb push_back
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
const int dim=1e5+10;
typedef long long ll;
typedef pair<int,int> pi;
int t,T,n,m,sr,a,b;

vector < int > d(dim,0),viz(dim,0),V[dim];

void BFS(int s)
{
    queue < int > qu;
    qu.push(s);
    viz[s]=1;
    while(!qu.empty())
    {
        int nod=qu.front();
        qu.pop();

        viz[nod]=2;
        for(unsigned int vecin:V[nod])
        {
            if(!viz[vecin])
            {
                viz[vecin]=1;
                qu.push(vecin);
                d[vecin]=d[nod]+1;
            }
        }
    }
}


int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    f>>n>>m>>sr;
    for(int i=1;i<=m;i++)
    {
        f>>a>>b;
        V[a].pb(b);
    }
    BFS(sr);
    for(int i=1;i<=n;i++)
    if(d[i]==0 && i!=sr) d[i]=-1;
    for(int i=1;i<=n;i++)
    g<<d[i]<<' ';

    return 0;
}