CSES – Planets Queries I

#include<bits/stdc++.h>
#define int long long
#define pii pair<int,int>
#define f first
#define s second
#define fastio ios_base::sync_with_stdio(0);cin.tie(0)
using namespace std;
//declare
const int maxn = 2e5+5;
int n,q,nxt[maxn],jump[maxn][32 + 1];
vector<int> ans;
//
void build(){
    for(int j=1;j<=32;j++){
        for(int i=1;i<=n;i++){
            jump[i][j] = jump[jump[i][j-1]][j-1];
        }
    }
}
int query(int a,int b){
    for(int i=0;i<=32;i++){
        if((1ll << i) & b){
            a = jump[a][i];
        }
    }
    return a;
}
signed main(){
    fastio;
    cin>>n>>q;
    for(int i=1;i<=n;i++) cin>>jump[i][0];
    build();
    while(q--){
        int a,b; cin>>a>>b;
        cout<<query(a,b)<<"\n";
    }
    return 0;
}