Cod sursa(job #2032118)

Utilizator ImbuzanRaduImbuzan Radu ImbuzanRadu Data 4 octombrie 2017 16:32:12
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.82 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;
int n,m,s,dist[100000];

vector<int>a[100000];
queue<int> q;

ifstream f("bfs.in");
ofstream g("bfs.out");

void BFS(int z){
  int x;
  q.push(z);
  while(!q.empty()){
    x=q.front();
    q.pop();
    for(auto i:a[z]){
      if(dist[i]==0 && i!=s){
        dist[i] = dist[x]+1;
        q.push(i);
      }
    }
  }
}

int main()
{
    f>>n>>m>>s;
    int o,p;
    for(int i=1;i<=m;i++){
      f>>o>>p;
      a[o].push_back(p);
    }

    for(int i=1;i<=n;i++){
      dist[i]=4000;
    }
    dist[s]=0;
    BFS(s);

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