Sort Colors

Problem statement

Given an array nums with n objects colored red, white, or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the order red, white, and blue.

We will use the integers 0, 1, and 2 to represent the color red, white, and blue, respectively.

You must solve this problem without using the library's sort function.

Example 1:

Input: nums = [2,0,2,1,1,0]Output: [0,0,1,1,2,2]

Example 2:

Input: nums = [2,0,1]Output: [0,1,2]

Constraints:

• n == nums.length
• 1 <= n <= 300
• nums[i] is either 0, 1, or 2.

Follow up: Could you come up with a one-pass algorithm using only constant extra space?

My solution

/**
 * @param {number[]} nums
 * @return {void} Do not return anything, modify nums in-place instead.
 */
var sortColors = function(nums) {
    let i =  0;
    let len = nums.length - 1;
    let j = 0;
    
    function swap(arr, i, j) {
        [arr[j], arr[i]] = [arr[i], arr[j]]
    }
    
    while (i <= len) {
        if (nums[i] === 0) {
            swap(nums, i, j);
            i++;
            j++
        } else if (nums[i] === 2) {
            swap(nums, i, len);
            len--;
        } else {
            i++;
        }
    }
};