Ladders

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;


int main() {
    ll n;

    cin >>n;

    ll a[n+1];
    ll position[n+1];
    for(ll i = 1; i<=n;i++) {

        ll tmp;
        cin >> tmp;
        a[i] = tmp;
        position[tmp] = i;
    }

    ll step = 0;
    ll steps[n] = {0};
    for(ll i = n; i>0; i--) {
        ll val = a[i];

        steps[i] = step;
        for(ll j = val; j<=n; j+=val) {
            //cout << "position " << position[j] << " with j " << j <<  " i " << i << endl;;
            if(position[j] > i) {
                //cout << "position " << position[j] << " min bw " << 1+steps[position[j]] << " and " << steps[i] << endl;
                steps[i] = min(1+steps[position[j]], steps[i]);
            }
            
        }
        step = 1 + steps[i];
    }

    cout << steps[1] << endl;
    // for(ll k = 1; k<=n; k++) {
    //     cout << steps[k] << " ";
    // }
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: ACCEPTED

Test 23

Verdict: ACCEPTED

Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED

Test 30

Verdict: ACCEPTED

Test 31

Verdict: ACCEPTED

Test 32

Verdict: ACCEPTED

Test 33

Verdict: ACCEPTED

Test 34

Verdict: ACCEPTED

Test 35

Verdict: ACCEPTED

Test 36

Verdict: ACCEPTED

Test 37

Verdict: ACCEPTED

Test 38

Verdict: ACCEPTED

Test 39

Verdict: ACCEPTED

Test 40

Verdict: ACCEPTED

Test 41

Verdict: ACCEPTED

Test 42

Verdict: ACCEPTED

Test 43

Verdict: ACCEPTED

Test 44

Verdict: ACCEPTED

Test 45

Verdict: WRONG ANSWER

Test 46

Verdict: ACCEPTED

Test 47

Verdict: ACCEPTED

Test 48

Verdict: ACCEPTED

Test 49

Verdict: ACCEPTED

Test 50

Verdict: ACCEPTED

Test 51

Verdict: ACCEPTED

Test 52

Verdict: WRONG ANSWER

Test 53

Verdict: WRONG ANSWER

Test 54

Verdict: ACCEPTED

Test 55

Verdict: ACCEPTED

Test 56

Verdict: ACCEPTED

Test 57

Verdict: ACCEPTED

Test 58

Verdict: ACCEPTED

Test 59

Verdict: ACCEPTED

Test 60

Verdict: ACCEPTED

Test 61

Verdict: WRONG ANSWER

Test 62

Verdict: WRONG ANSWER

Test 63

Verdict: ACCEPTED

Test 64

Verdict: ACCEPTED

Test 65

Verdict: WRONG ANSWER

Test 66

Verdict: ACCEPTED

Test 67

Verdict: WRONG ANSWER

Test 68

Verdict: ACCEPTED

Test 69

Verdict: ACCEPTED

Test 70

Verdict: WRONG ANSWER

Test 71

Verdict: WRONG ANSWER