Arrays 101 Code from Java to Go(A Better Repeated Deletion Algorithm - Intro)

The nested loop Code

Java

class Solution {
    public int removeDuplicates(int[] nums) {

        // The initial length is simply the capacity.
        int length = nums.length;

        // Assume the last element is always unique.
        // Then for each element, delete it iff it is
        // the same as the one after it. Use our deletion
        // algorithm for deleting from any index.
        for (int i = length - 2; i >= 0; i--) {
            if (nums[i] == nums[i + 1]) {
                // Delete the element at index i, using our standard
                // deletion algorithm we learned.
                for (int j = i + 1; j < length; j++) {
                    nums[j - 1] = nums[j];
                }
                // Reduce the length by 1.
                length--;
            }
        }
        // Return the new length.
        return length;
    }
}

Go

func removeDuplicates(nums []int) int{
    // The initial length is simply the capacity.
    length := len(nums)

    // Assume the last element is always unique.
    // Then for each element, delete it if it is
    // the same as the one after it. Use our deletion
    // algorithm for deleting from any index.
    for i:=length-2; i>=0; i--{
        if nums[i] == nums[i+1]{
            // Delete the element at index i, using our standard
            // deletion algorithm we learned.
            for j:= i+1; j<length; j++{
                nums[j-1] = nums[j]
            }
            // Reduce the length by 1
            length--
        }
    }
    // Return the new length.
     return length;
}

Result Array of unique elements Code

Java

public int[] copyWithRemovedDuplicates(int[] nums) {

  // Check for edge cases.
  if (nums == null || nums.length == 0) {
      return nums;
  }

  // Count how many unique elements are in the Array.
  int uniqueNumbers = 0;
  for (int i = 0; i < nums.length; i++) {
      // An element should be counted as unique if it's the first
      // element in the Array, or is different to the one before it.
      if (i == 0 || nums[i] != nums[i - 1]) {
          uniqueNumbers++;
      }
  }

  // Create a result Array.
  int[] result = new int[uniqueNumbers];

  // Write the unique elements into the result Array.
  int positionInResult = 0;
  for (int i = 0; i < nums.length; i++) {
    // Same condition as in the previous loop. Except this time, we can write
    // each unique number into the result Array instead of just counting them.
      if (i == 0 || nums[i] != nums[i - 1]) {
          result[positionInResult] = nums[i];
          positionInResult++;
      }
  }
  return result;
}

Go

func copyWithRemovedDuplicates(nums []int) []int {

    // Check for edge cases.
    if nums == nil || len(nums) == 0 {
        return nums
    }

    // Count how many unique elements are in the Array
    uniqueNumbers := 0
    for i := 0; i < len(nums); i++ {
        // An element should be counted as unique if it's the first
        // element in the Array, or is different to the one before it.
        if i == 0 || nums[i] != nums[i-1] {
            uniqueNumbers++
        }
    }

    // Create a result Array.
    result := make([]int, uniqueNumbers)

    // Write the unique elements into the result Array.
    positionInResult :=0
    for i:=0; i<len(nums); i++{
        if i == 0 || nums[i] != nums[i-1]{
            result[positionInResult] = nums[i]
            positionInResult++
        }
    }
    return result
}