Cod sursa(job #1880262)

Utilizator JavaAlexDinu Alexandru JavaAlex Data 15 februarie 2017 17:26:46
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.78 kb
#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

ifstream r("bfs.in");
ofstream w("bfs.out");

const int N = 1000001;
vector<int> v[N];
int n, m, q[N], d[N], p, u, x0;

void citire(){
    int i, x, y;
    r >> n >> m >> x0;
    for(i=0; i<m; i++){
        r >> x >> y;
        v[x].push_back(y);
    }
    r.close();
}

void bfs(int x){
    int i, t, y;
    for(i=1; i<=n; i++) d[i] = -1;
    p=0; u=-1;
    q[++u] = x;
    d[x] = 0;
    while(p <= u){
        t = q[p++];
        for(i=0; i<v[t].size(); i++){
            y = v[t][i];
            if(d[y] == -1){
                q[++u] = y;
                d[y] = 1 + d[t];
            }
        }
    }
}

int main()
{
    int i;
    citire();
    bfs(x0);
    for(i=1; i<=n; i++) w<<d[i]<<" ";
    return 0;
}