Cod sursa(job #1425863)

Utilizator nacrocRadu C nacroc Data 28 aprilie 2015 11:30:56
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.92 kb
#include <stdio.h>
#include <string.h>
#include <queue>
#include <vector>
#define NMAX 100005

using namespace std;

vector <int> v[NMAX];
queue <int> q;
int cost[NMAX], st;

void bfs(){
    int val;
    memset(cost, -1, sizeof(cost));
    q.push(st);
    cost[st] = 0;
    while(!q.empty()){
        val = q.front();
        q.pop();
        for(vector <int> :: iterator it = v[val].begin(); it != v[val].end(); ++it)
            if(cost[*it] == -1){
                q.push(*it);
                cost[*it] = cost[val] + 1;
            }
    }
}

int main(){
    freopen("bfs.in", "r", stdin);
    freopen("bfs.out", "w", stdout);
    int N, M, x, y;
    scanf("%d %d %d", &N, &M, &st);
    for(int i = 1; i <= M; ++i){
        scanf("%d %d", &x, &y);
        v[x].push_back(y);
    }
    bfs();
    for(int i = 1; i <= N; ++i)
        printf("%d ", cost[i]);
    printf("\n");
    return 0;
}