Cod sursa(job #1322872)

Utilizator c0rn1Goran Cornel c0rn1 Data 20 ianuarie 2015 14:39:16
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.14 kb
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <queue>
#define NMAX 100008
#define inf 0x3f3f3f3f

using namespace std;

int n, m, s, best[NMAX];
vector<int> v[NMAX];
queue<int> q;

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

}

void bfs(){

    vector<int>::iterator it;
    q.push(s);
    memset(best, inf, sizeof(best));
    best[s] = 0;
    int nodc;
    while (!q.empty()){

        nodc = q.front();
        q.pop();
        for (it = v[nodc].begin(); it!=v[nodc].end(); it++){
            if (best[nodc] + 1 <= best[*it]){
                best[*it] = best[nodc] + 1;
                q.push(*it);
            }
        }

    }
}

int main()
{
    freopen("bfs.in", "r", stdin);
    freopen("bfs.out", "w", stdout);
    citire();
    bfs();
    for (int i=1; i<=n; i++){
        if (best[i] == inf){
            printf("-1 ");
        }
        else {
            printf("%d ", best[i]);
        }
    }


    return 0;
}