Cod sursa(job #2109873)

Utilizator SineMineSzasz Bogdan SineMine Data 20 ianuarie 2018 11:01:40
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.86 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#define MaxN 100004

using namespace std;

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

vector < int > G[MaxN];
int V[MaxN];
int n, m, S, x, y, urm_x;

void read()
{
    fin >> n >> m >> S;

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

void bfs()
{
    queue < int > Q;
    Q.push(S);
    V[S] = 1;

    while(!Q.empty())
    {
        x = Q.front();
        Q.pop();
        int l = G[x].size();

        for(int i = 0 ;i < l; ++i)
        {
            urm_x = G[x][i];

            if(not V[urm_x])
                V[urm_x] = V[x] + 1, Q.push(urm_x);
        }
    }
}

int main()
{
    read();
    bfs();

    for(int i = 1; i <= n; ++i)
        fout << V[i] - 1 << " ";
    return 0;
}