In this HackerEarth The Psychic Type problem solution Alakazam has the unique ability to teleport itself during fights. He has realized that he can use this ability not just in Pokemon fights, but also during real-time manipulation of arrays. Abra, his non-evolution form has an interesting array of N integers, A1, A2, ..., AN-1, AN.

Since Alakazam wants to try his teleportation power on arrays too, he decides to formalize it: he can move from any position I to a position A[i] in an array of the world. Now, he is currently standing at a position he calls S. He wants you to figure out if he can reach position E.


HackerEarth The Psychic Type problem solution


HackerEarth The Psychic Type problem solution.

#include <iostream>
#include <sstream>
#include <fstream>
#include <string>
#include <iomanip>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <algorithm>
#include <functional>
#include <utility>
#include <bitset>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <cassert>
using namespace std;

#define rep(i,n) for(int i=0;i<n;i++)
#define ll  long long int
#define pi pair<ll,ll>
#define pii pair<ll,pi>
#define f first
#define mp make_pair
#define mod 1000000007
#define s second
#define pb push_back
int A[100011];
bool vis[100011];
int main(){

    int N;
    cin >> N;
    for(int i=1;i<=N;i++){
      cin >> A[i];
      assert(A[i]>=1 and A[i]<=N);
    }
    int S,E;
    cin >> S >> E;
    assert(S>=1 and S<=N and E>=1 and E<=N);
    while(!vis[S]){
      vis[S]=1;
      S=A[S];
    }
    if(vis[E]){
      cout<<"Yes\n";
    }
    else{
      cout<<"No\n";
    }
}