Cod sursa(job #1519398)

Utilizator beatrice01Ferco Beatrice beatrice01 Data 7 noiembrie 2015 12:06:17
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.01 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

const int maxn=100005;
int n,m,s,dist[maxn];
vector <int> g[maxn];

void  bfs(int st)
{
  for(int i=1;i<=n;i++)
     dist[i]=-1;
     /// echivalenta cu memset (dist,-1,sizeof(dist));
   queue <int > q;
   dist[st]=0;
   q.push(st);
   while(!q.empty())
     {
         int node = q.front();
         q.pop();
         for(int i=0; i<int (g[node].size()); i++)
            {
                int vecin = g[node][i];
                if(dist[vecin]== -1)
                   {
                       dist[vecin] = dist[node] +1;
                       q.push (vecin);
                    }
            }
     }
}

int main()
{
    ifstream fin("bfs.in");
    ofstream fout("bfs.out");
    fin>>n>>m>>s;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        fin>>x>>y;
        g[x].push_back(y); /// x->y
    }
    bfs(s);
    for(int i=1;i<=n;i++)
     fout<<dist[i]<<" ";
    return 0;
}