Cod sursa(job #2105490)

Utilizator calinfloreaCalin Florea calinflorea Data 13 ianuarie 2018 14:24:22
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.06 kb
#include <bits/stdc++.h>
#define NMax 100006
#define oo (1 << 30)
using namespace std;

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

vector <int> L[NMax];
int drum[NMax];
int n, m, k;
queue <int> q;
void Citire()
{
    int i, x, y;

    fin >> n >> m >> k;

    for(i = 1; i <= m; i++)
    {
        fin >> x >> y;
        L[x].push_back(y);

    }
}

void Initializare()
{
    int i;

    for(i = 1; i <= n; i++)
        drum[i] = oo;
}
void BFS()
{
    int i, j, nod;

    q.push(k);
    drum[k] = 0;

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

        for(j = 0; j < L[i].size(); j++)
        {
            nod = L[i][j];
            if(drum[nod] > drum[i] + 1)
            {
                drum[nod] = drum[i] + 1;
                q.push(nod);
            }
        }
    }

    for(i = 1; i <= n; i++)
        if(drum[i] != oo)
            fout << drum[i] << " ";
        else
            fout << "-1 ";
}
int main()
{
    Citire();
    Initializare();
    BFS();
    return 0;
}