26. Remove Duplicates from Sorted Array

/**
26. Remove Duplicates from Sorted Array
https://leetcode.com/problems/remove-duplicates-from-sorted-array/description/
*/
class Solution {
    fun removeDuplicates(nums: IntArray): Int {
        if (nums==null || nums.isEmpty()){
            return 0
        }
        val n = nums.size
        val tempArray = IntArray(n)
        var j = 0
        for (i in 0 until n-1){
            if (nums[i]!=nums[i+1]){
                tempArray[j++] = nums[i]
            }
        }
        //add the last element, because it not save in loop for
        tempArray[j++] = nums[n-1]
        //modify original array 
        for (i in 0 until j){
            nums[i] = tempArray[i]
        }
        //return new size of array
        return j
    }
}