Cod sursa(job #1118973)

Utilizator visanrVisan Radu visanr Data 24 februarie 2014 14:09:07
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.9 kb
#include <cstdio>
#include <queue>
#include <vector>
using namespace std;

const int NMAX = 100010;

int N, M, X, Y, Dist[NMAX], S;
vector<int> G[NMAX];

void BFS()
{
    for(int i = 1; i <= N; ++ i) Dist[i] = -1;
    Dist[S] = 0;
    queue<int> Q;
    Q.push(S);

    while(!Q.empty())
    {
        int Node = Q.front();
        Q.pop();

        for(vector<int> :: iterator it = G[Node].begin(); it != G[Node].end(); ++ it)
            if(Dist[*it] == -1)
            {
                Dist[*it] = Dist[Node] + 1;
                Q.push(*it);
            }
    }

    for(int i = 1; i <= N; ++ i)
        printf("%i ", Dist[i]);
}

int main()
{
    freopen("bfs.in", "r", stdin);
    freopen("bfs.out", "w", stdout);

    scanf("%i %i %i", &N, &M, &S);
    for(int i = 1; i <= M; ++ i)
    {
        scanf("%i %i", &X, &Y);
        G[X].push_back(Y);
    }

    BFS();
}