DSA Sum two numbers represented in a array

Using C++

Solution might be incorrect, this is something I solved and posted.

#include <iostream>
using namespace std;

int main() {
  // Sum two numbers represented in array
  int arr1[] = {9, 2, 3};
  int arr2[] = {2, 4, 9};
  //  this array may be +1 size because suppose 99+99=198

  int arr3[4]={0};
  
  int arr3Size = sizeof(arr3) / sizeof(int);

  int i = sizeof(arr1) / sizeof(int);
  int j = sizeof(arr2) / sizeof(int);
  int k = sizeof(arr3) / sizeof(int);
  // run loop based on the bigger size array
  int singleNumberSum, sumLastDigit;
  int carry = 0;
  int arr1Item;
  int arr2Item;
  while (j > 0 || i > 0) {
    arr1Item = 0;
    arr2Item = 0;
    if (i >= 1) {
      arr1Item = arr1[i - 1];
      cout << "first item " << arr1Item << endl;
    }
    if (j >= 1) {
      arr2item = arr2[j - 1];
      cout << "second item " << arr2Item << endl;
    }
    singleNumberSum = arr1Item + arr2Item + carry;
    cout << "sum " << singleNumberSum << endl;
    // suppose sum is 14, take 4 and 1 apart
    sumLastDigit = singleNumberSum % 10; // 14->10 ekum 10 bache 4
    carry = singleNumberSum / 10;        // 14/10->1.4->1
    arr3[k - 1] = sumLastDigit;
    cout << "sumLastDigit " << sumLastDigit << endl;
    cout << "carry " << carry << endl << endl;

    i--;
    j--;
    k--;
  }
  if (carry > 0) {
    arr3[k - 1] = carry;
  }
  //print answer
  for (int i = 0; i < arr7Size; i++) {
    cout << arr3[i] << " ";
  }
}