Cod sursa(job #2376768)

Utilizator danhHarangus Dan danh Data 8 martie 2019 17:31:53
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <cstring>
#include <queue>
using namespace std;

ifstream fin("bfs.in");
ofstream fout("bfs.out");

const int MAX = 100005;

vector<int>lista[MAX];
queue<int>q;

int n, m , S;

int drum[MAX];

void BFS(int nod)
{
    q.push(nod);
    drum[nod] = 1;

    while(!q.empty())
    {
        nod = q.front();
        q.pop();

        for(int el:lista[nod])
        {
            if(!drum[el])
            {
                drum[el] = drum[nod]+1;
                q.push(el);
            }
        }
    }
}


int main()
{
    int i;

    fin>>n>>m>>S;

    int x,y;
    for(i=1; i<=m; i++)
    {
        fin>>x>>y;
        lista[x].push_back(y);
    }

    BFS(S);

    for(i=1; i<=n; i++)
    {
        if(drum[i] == 0)
        {
            fout<<"-1 ";
        }
        else
        {
            fout<<drum[i]-1<<' ';
        }
    }

    fin.close();
    fout.close();
    return 0;
}