Problem p02716 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <iostream>
using namespace std;
#include <vector>
#define int long long int
int function(int arr[], int initial, int final, int curr, int memo[][3]) {
  if (initial > final) {
    if (curr > 0) {
      return -100000000000000;
    } else
      return 0;
  }
  if (memo[initial][curr] != -1)
    return memo[initial][curr];
  else {
    if (curr == 0) {
      int val = arr[initial] + function(arr, initial + 2, final, curr, memo);
      memo[initial][curr] = val;
      return memo[initial][curr];
    } else {
      int val1 = arr[initial] + function(arr, initial + 2, final, curr, memo);
      int val2 =
          arr[initial] + function(arr, initial + 3, final, curr - 1, memo);
      memo[initial][curr] = max(val1, val2);
      return memo[initial][curr];
    }
  }
}
int function2(int arr[], int initial, int final, int curr, int memo[][2]) {
  if (initial > final) {
    if (curr == 0 && initial == final + 4)
      return -1000000000000000;
    if (curr > 0)
      return -1000000000000000;
    return 0;
  }
  if (memo[initial][curr] != -1)
    return memo[initial][curr];
  else {
    if (curr == 0) {

      int x = arr[initial] + function2(arr, initial + 2, final, curr, memo);
      memo[initial][curr] = x;
      return memo[initial][curr];
    } else {
      int x = arr[initial] + function2(arr, initial + 2, final, curr, memo);
      int y = arr[initial] + function2(arr, initial + 4, final, curr - 1, memo);
      memo[initial][curr] = max(x, y);
      return memo[initial][curr];
    }
  }
}
int32_t main() {
  int n;
  cin >> n;
  int arr[n + 1];
  int j;
  for (j = 1; j <= n; j++) {
    cin >> arr[j];
  }
  int memo[n + 1][3];
  int i;
  for (i = 0; i <= n; i++) {
    for (j = 0; j < 3; j++) {
      memo[i][j] = -1;
    }
  }
  if (n % 2 == 0) {
    int val1 = function(arr, 1, n, 1, memo);
    int val2 = function(arr, 2, n, 0, memo);
    cout << max(val1, val2) << endl;
  } else {
    int val1 = function(arr, 1, n, 2, memo);
    int val2 = function(arr, 2, n, 1, memo);
    int val3 = function(arr, 3, n, 0, memo);
    int answer2 = max(val1, max(val2, val3));
    int memo2[n + 1][2];
    for (i = 0; i <= n; i++) {
      memo2[i][0] = -1;
      memo2[i][1] = -1;
    }
    int val4 = function2(arr, 1, n, 1, memo2);
    answer2 = max(answer2, val4);
    cout << answer2 << endl;
  }
}


Error: TLE

Fixed submission:

#include <iostream>
using namespace std;
#include <vector>
#define int long long int
int function(int arr[], int initial, int final, int curr, int memo[][3]) {
  if (initial > final) {
    if (curr > 0) {
      return -100000000000000;
    } else
      return 0;
  } else {
    if (curr == 0) {
      int val = arr[initial] + function(arr, initial + 2, final, curr, memo);
      memo[initial][curr] = val;
      return memo[initial][curr];
    } else {
      int val1 = arr[initial] + function(arr, initial + 2, final, curr, memo);
      int val2 =
          arr[initial] + function(arr, initial + 3, final, curr - 1, memo);
      memo[initial][curr] = max(val1, val2);
      return memo[initial][curr];
    }
  }
}
int function2(int arr[], int initial, int final, int curr, int memo[][2]) {
  if (initial > final) {
    if (curr == 0 && initial == final + 4)
      return -1000000000000000;
    if (curr > 0)
      return -1000000000000000;
    return 0;
  }
  if (memo[initial][curr] != -1)
    return memo[initial][curr];
  else {
    if (curr == 0) {

      int x = arr[initial] + function2(arr, initial + 2, final, curr, memo);
      memo[initial][curr] = x;
      return memo[initial][curr];
    } else {
      int x = arr[initial] + function2(arr, initial + 2, final, curr, memo);
      int y = arr[initial] + function2(arr, initial + 4, final, curr - 1, memo);
      memo[initial][curr] = max(x, y);
      return memo[initial][curr];
    }
  }
}
int32_t main() {
  int n;
  cin >> n;
  int arr[n + 1];
  int j;
  for (j = 1; j <= n; j++) {
    cin >> arr[j];
  }
  int memo[n + 1][3];
  int i;
  for (i = 0; i <= n; i++) {
    for (j = 0; j < 3; j++) {
      memo[i][j] = -1;
    }
  }
  if (n % 2 == 0) {
    int val1 = function(arr, 1, n, 1, memo);
    int val2 = function(arr, 2, n, 0, memo);
    cout << max(val1, val2) << endl;
  } else {
    int val1 = function(arr, 1, n, 2, memo);
    int val2 = function(arr, 2, n, 1, memo);
    int val3 = function(arr, 3, n, 0, memo);
    int answer2 = max(val1, max(val2, val3));
    int memo2[n + 1][2];
    for (i = 0; i <= n; i++) {
      memo2[i][0] = -1;
      memo2[i][1] = -1;
    }
    int val4 = function2(arr, 1, n, 1, memo2);
    answer2 = max(answer2, val4);
    cout << answer2 << endl;
  }
}