Card game

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

#define N 10000001

typedef long long ll;
ll sum[N];
void debug_print(int n) {
  for (int i = 0; i < n; i++) {
    cout << sum[i] << " ";
  }
  cout << "\n";
}

ll get_max(int *arr, int n, int i) {
  if (sum[i]) {
    return sum[i];
  }
  if (i == n - 1) {
    sum[i] = 0;
    return sum[i];
  }

  if (i >= n - 4) {
    sum[i] = arr[i];
    return sum[i];
  }

  for (int j = i + 3; j < n; j++) {
    sum[i] = max(sum[i], get_max(arr, n, j));
  }
  sum[i] += arr[i];
  return sum[i];
}

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);

  int n;
  cin >> n;
  int arr[n];

  for (int i = 0; i < n; i++) {
    cin >> arr[i];
  }

  ll m = 0;
  for (int i = 1; i < n - 1; i++) {
    if (i <= 3) {
      sum[n - i - 1] = arr[n - i - 1];
    } else {
      sum[n - i - 1] =
          arr[n - i - 1] +
          max(
              max(sum[n - i - 1 + 3], sum[n - i - 1 + 4]),
              sum[n - i - 1 + 5]
          );
    }
    if (m < sum[n - i - 1]) {
      m = sum[n - i - 1];
    }
  }

  cout << m << endl;
  return 0;
}

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