Cod sursa(job #1847972)

Utilizator CriistinaMicula Cristina Criistina Data 15 ianuarie 2017 12:07:21
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.77 kb
#include <iostream>
#include <vector>
#include <queue>
#include <fstream>
#define Nmax 100001

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

vector <int> gr[Nmax];
queue <int> dr;
int n, m,s;
int v[Nmax];

int main()
{
    f>>n>>m>>s;
    int x, y;
    for(int i=1;i<=m;i++)
    {
        f>>x>>y;
        gr[x].push_back(y);
    }
    dr.push(s);
    while(!dr.empty())
    {
        int fr=dr.front();
        dr.pop();
        for(auto i:gr[fr])
        {
            if(v[i]==0 && i!=s){
                v[i]=v[fr]+1;
                dr.push(i);
            }
        }
    }
    for(int i=1;i<=n;i++)
    {
        if(v[i]==0 && i!=s)
            g<<"-1 ";
        else
            g<<v[i]<<" ";
    }
    return 0;
}