Cod sursa(job #1699927)

Utilizator madalina41724Madalina Marin madalina41724 Data 8 mai 2016 20:50:08
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.68 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");

vector <int> v[100005];
queue  <int> q;
int n,m,s,d[100005],use[100005];

void BFS(int x)
{ int i;
  q.push(x); d[x]=0;
   use[x]=1;
  while(!q.empty())
  { x=q.front(); q.pop();

    for(i=0;i<v[x].size();i++)
     if (!use[v[x][i]])
      {q.push(v[x][i]); d[v[x][i]]=d[x]+1; use[v[x][i]]=1;}
  }
}

int main()
{ int i,x,y;
    f>>n>>m>>s;
    for(i=1;i<=m;i++)
    { f>>x>>y;
      v[x].push_back(y);
    }

    BFS(s);

   for(i=1;i<=n;i++)
    if (!d[i] && i!=s) g<<"-1 "; else g<<d[i]<<" ";
    return 0;
}