Cod sursa(job #2718570)

Utilizator BogdanRuleaBogdan Rulea BogdanRulea Data 8 martie 2021 20:15:31
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.86 kb
#include <fstream>
#include <queue>
#include <vector>
using namespace std;
ifstream cin("bfs.in");
ofstream cout("bfs.out");

int n,m,s,x,y;
const int NMAX = 1e5+1;
vector <int> g[NMAX];
int viz[NMAX],ans[NMAX];
void read()
{
    cin>>n>>m>>s;
    while(m--)
    {
        cin>>x>>y;
        g[x].push_back(y);
    }
}
queue <int> q;
void bfs(int nod)
{
    viz[nod]=1;
    q.push(nod);
    while(!q.empty())
    {
        int first = q.front();
        for(auto it:g[first])
        {
            if(!viz[it])
            {
                viz[it]=1;
                ans[it]=ans[first]+1;
                q.push(it);
            }
        }
        q.pop();
    }
}
void afisare(int s)
{
    for(int i=1;i<=n;i++)
        cout<<(ans[i]==0 && i!=s?-1:ans[i])<<" ";
}
int main()
{
  read();
  bfs(s);
  afisare(s);
    return 0;
}