Mock interview on Oct. 11, 2020 - merge two sorted array

MergeTwoSortedArray.cs

/* 
Your previous Plain Text content is preserved below:

Given 2 arrays sorted in ascending order, explain and implement an optimal algorithm to merge the arrays. 
Example: 
  A = [1, 2, 3] 
  B = [4, 5, 6] and
  Output =  [1, 2, 3, 4, 5, 6]
  
  [1, 2, 3] -> 
  -- -   -
  [4, 5, 6]
  --
  [1,2, 3, 4, 5, 6] - 
  */
  // O(N + M), N length of sorted1, M is length of second array
  public int[] mergeArrays(int[] sorted1, int[] sorted2)
  {
    if(sorted1 == null || sorted2 == null)
    return new int[0];
    
    if(sorted1.Length == 0)
    return sorted2;
    
    if(sorted2.Length == 0)
    return sorted1; 
    
    var start1 = 0;
    var start2 = 0; 
    
    var length1 = sorted1.Length;
    var length2 = sorted2.Length; 
    
    var merged = new int[length1 + length2]
    
    int index = 0; 
    while(start1 < length1 || start2 < length2)
    {
      if(start1 >= length1)
      {
        merged[index++] = start2[start2];
        start2++;
      }
      else if(strat2 >= length2)
      {
        merged[index++] = start2[start1];
        start1++;
      }
      else 
      {
        if(sorted[start1] > sorted2[start2])
        {
        merged[index++] = sorted2[start2++];
        }
        else 
        {
        merged[index++] = sorted1[start1++];
        }
      }    
    
      //index++; 
    }
    
    return merged; 
  }