Cod sursa(job #2390112)

Utilizator 88marin88Marin Marian 88marin88 Data 27 martie 2019 19:31:42
Problema BFS - Parcurgere in latime Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.06 kb
#include<bits/stdc++.h> 
using namespace std;

ifstream fin("bfs.in");
ofstream fout("bfs.out");
 
int n,m,x;
//vector < vector <int> >v;
vector<int> v[100001];
 
int dist[100001];
int viz[100001];
 
void read()
{
    fin>>n>>m>>x;
    int val1,val2,i;
    for(i=1; i<=m; i++)
       {
           fin>>val1>>val2;
           v[val1].push_back(val2);
       }
}
 
void bfs(int x){
    int i;
    queue<int>C;
    C.push(x);
    viz[x]=1;
    while(!C.empty())
         {
             int node=C.front();
             C.pop();
             viz[node]=1;
             int ct=v[node].size();
             for(i=0; i<ct; i++)
                 {
                   int val=v[node][i];
                   if(viz[val]==0) {dist[val]=dist[node]+1; C.push(val);}
                 }
         }
}
 
int main(){
    read();
    for(int i=1; i<=n; i++)
         dist[i]=n;
    dist[x]=0;
    bfs(x);
    for(int i=1; i<=n; i++)
         if(dist[i]!=n) fout<<dist[i]<<" ";
         else if(i==x) fout<<0<<" ";
              else fout<<-1<<" ";
}