Cod sursa(job #1001099)

Utilizator alexx.cosmaCosma Cristian Alexandru alexx.cosma Data 24 septembrie 2013 15:12:48
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.06 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

int N,M,S;

const int maxN = 100010;

vector<int>adj[maxN];

int vis[maxN];
int dist[maxN];

void bfs(int S);

int main()
{
    fin>>N;
    fin>>M;
    fin>>S;

    for(int i=0; i<M; i++)
    {
        int source,dest;
        fin>>source;
        fin>>dest;
        adj[source].push_back(dest);
    }

    bfs(S);
    return 0;
}

void bfs(int S)
{
    for(int i=0;i<maxN;i++){
        dist[i]=-1;
    }
    queue<int> q;
    q.push(S);
    vis[S]++;
    dist[S]=0;

    while(!q.empty()){
        int t = q.front();
        q.pop();
        int nrNeigh = adj[t].size();
        for(int i=0;i<nrNeigh;i++){
            int u = adj[t][i];
            if(vis[u] == 0){
                dist[u]=dist[t]+1;
                vis[u]++;
                q.push(u);
            }
        }
    }

    for(int i=1;i<=N;i++){
        fout << dist[i] << " ";
    }
    fout<<endl;
}