Cod sursa(job #2423637)

Utilizator IamandiiAnaIamandii Ana Maria IamandiiAna Data 21 mai 2019 19:48:44
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.88 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

void bfs(int nod_start,vector<vector<int>>&G,vector<int>&d)
{
    queue<int>coada;
    coada.push(nod_start);
    d[nod_start]=0;
    while(!coada.empty())
    {
        int aux=coada.front();
        coada.pop();
        for(auto vecin:G[aux])
            if(d[vecin]>d[aux]+1)
            {
                coada.push(vecin);
                d[vecin]=d[aux]+1;
            }
    }
}

int main()
{
    int n,m,i,a,b,s;
    f>>n>>m>>s;
    vector<vector<int>>G(n+1);
    vector<int>d(n+1,n+1);
    for(i=1; i<=m; i++)
    {
        f>>a>>b;
        G[a].push_back(b);
    }
    bfs(s,G,d);
    for(i=1; i<=n; i++)
    {
        if(d[i]==n+1)
            d[i]=-1;
        g<<d[i]<<" ";
    }
    return 0;
}