Cod sursa(job #791200)

Utilizator harababurelPuscas Sergiu harababurel Data 23 septembrie 2012 13:00:40
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.03 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>
#define nmax 100005
using namespace std;

vector <int> v[nmax];
int cost[nmax];
bool vizitat[nmax];
queue <int> c;
int n, m, s, a, b, nod;

void bfs() {
    cost[s] = 0;
    c.push(s);

    while(!c.empty()) {
        nod = c.front();
        vizitat[nod] = true;
        c.pop();

        for(int i=0; i<v[nod].size(); i++) {
            if(!vizitat[ v[nod][i] ]) {
                c.push(v[nod][i]);
                cost[v[nod][i]] = cost[nod] + 1;
                vizitat[v[nod][i]] = true;
            }
        }
    }

}




int main() {
    ifstream f("bfs.in");
    ofstream g("bfs.out");

    f>>n>>m>>s;

    for(int i=1; i<=m; i++) {
        f>>a>>b;
        v[a].push_back(b);
    }
    for(int i=0; i<=n; i++) {
        vizitat[i] = false;
        cost[i] = -1;
    }

    bfs();

    for(int i=1; i<=n; i++) g<<cost[i]<<" ";
    g<<"\n";

    f.close();
    g.close();
    return 0;
}