removeDuplicates.js

/**
 * https://leetcode.com/problems/remove-duplicates-from-sorted-array/
 * 
 * Given a sorted array nums, remove the duplicates in-place such that each element appear only once and return the new length.
 * 
 * Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.
 * 
 * Example 1:
 * 
 * Given nums = [1,1,2],
 * 
 * Your function should return length = 2, with the first two elements of nums being 1 and 2 respectively.
 * 
 * It doesn't matter what you leave beyond the returned length.
 * Example 2:
 * 
 * Given nums = [0,0,1,1,1,2,2,3,3,4],
 * 
 * Your function should return length = 5, with the first five elements of nums being modified to 0, 1, 2, 3, and 4 respectively.
 * 
 * It doesn't matter what values are set beyond the returned length.
 * Clarification:
 * 
 * Confused why the returned value is an integer but your answer is an array?
 * 
 * Note that the input array is passed in by reference, which means modification to the input array will be known to the caller as well.
 * 
 * Internally you can think of this:
 * 
 * // nums is passed in by reference. (i.e., without making a copy)
 * int len = removeDuplicates(nums);
 * 
 * // any modification to nums in your function would be known by the caller.
 * // using the length returned by your function, it prints the first len elements.
 * for (int i = 0; i < len; i++) {
 *     print(nums[i]);
 * }
 * 
 * @param {number[]} nums
 * @return {number}
 */
var removeDuplicates = function(nums) {
    if (nums.length == 0) return 0
    let pointer = 0
    for (let i = 1; i < nums.length; i++) {
        if (nums[i] != nums[pointer]) {
            pointer++
            nums[pointer] = nums[i]

        }
    }

    return pointer + 1
};