Cod sursa(job #1435899)

Utilizator tsubyRazvan Idomir tsuby Data 14 mai 2015 19:02:49
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
#include <queue>

#define NMAX 100005
using namespace std;

int n, m, s; // s == nod sursa
queue<int> coada;
vector< vector<int> > a(NMAX);
int cost[NMAX];

void citire() {
    int x, y;
    scanf("%d %d %d", &n, &m, &s);
    for(int i = 0; i < m; i++) {
        scanf("%d %d", &x, &y);
        a[x].push_back(y);
    }
}

void fill_cost() {
    for(int i = 0; i <= n; i++)
        cost[i] = -1;
}
void bfs(int s) {
    //memset(cost, -1, sizeof(cost));
    fill_cost();
    cost[s] = 0;
    coada.push(s);

    while(!coada.empty()) {
        int i = coada.front();
        for(int j = 0; j < a[i].size(); j++)
            if(cost[a[i][j]] == -1) {
                coada.push(a[i][j]);
                cost[a[i][j]] = cost[i] + 1;
            }
        coada.pop();
    }
}

int main()
{
    freopen("bfs.in", "r", stdin);
    freopen("bfs.out", "w", stdout);
    citire();
    bfs(s);
    for(int i = 1; i <= n; i++)
        printf("%d ", cost[i]);
    return 0;
}