Cod sursa(job #2125467)

Utilizator B_RazvanBaboiu Razvan B_Razvan Data 8 februarie 2018 14:59:21
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.08 kb
#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#define NMAX 100005

using namespace std;

int N, M, S, nrArce[NMAX];
bool viz[NMAX];
vector <int> G[NMAX];
vector <int>::iterator it;
queue <int> Q;

void read()
{
    scanf("%d %d %d", &N, &M, &S);
    for(int i=1; i<=M; ++i)
    {
        int a, b;
        scanf("%d %d", &a, &b);
        G[a].push_back(b);
    }
    for(int i=1; i<=N; ++i)
        nrArce[i] = -1;
}

void bfs()
{
    Q.push(S);
    nrArce[S] = 0;
    viz[S] = true;
    while(!Q.empty())
    {
        int nod = Q.front();
        Q.pop();
        for(it = G[nod].begin(); it != G[nod].end(); ++it)
            if(viz[*it] == false)
            {
                viz[*it] = true;
                nrArce[*it] = nrArce[nod] + 1;
                Q.push(*it);
            }
    }
}

void print()
{
    for(int i=1; i<=N; ++i)
        printf("%d ", nrArce[i]);
}

int main()
{
    freopen("bfs.in", "r", stdin);
    freopen("bfs.out", "w", stdout);
    read();
    bfs();
    print();
    return 0;
}