Cod sursa(job #1306352)

Utilizator StarGold2Emanuel Nrx StarGold2 Data 30 decembrie 2014 21:36:48
Problema BFS - Parcurgere in latime Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 0.98 kb
#include <fstream>
#include <vector>
using namespace std;

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

int n, m, i, j, k, ok, minim, s;
int vizit[100100], cost[100100];
int coada[100100], x, y,  p,  u;
vector < int > v[100100];

void write(){
    for(i = 1; i <= n; i ++)
        fout << cost[i] << " ";
    return;
}

void initialize(){
    p = 1; u = 1; coada[1] = s;
    for(i = 1; i <= n; i ++)
        cost[i] = -1;
    return;
}

void bfs(int val){
    vizit[val] = 1;
    for(int i = 0; i < v[val].size(); i ++){
        if(vizit[v[val][i]] == 0){
            cost[v[val][i]] = cost[val] + 1;
            u ++; coada[u] = v[val][i];
        }
    }
    if(++ p <= u)
        bfs(coada[p]);
    return;
}

void read(){
    fin >> n >> m >> s;
    initialize(); cost[s] = 0;
    for(i = 1; i <= m; i ++){
        fin >> x >> y;
        v[x].push_back(y);
    }
    return;
}

int main(){
    read();
    bfs(s);
    write();
    return 0;
}