[LeetCode] 75. Sort Colors

 1 /**
 2  * @param {number[]} nums
 3  * @return {void} Do not return anything, modify nums in-place instead.
 4  */
 5 var sortColors = function(nums) {
 6     // corner case
 7     if (nums.length === 0 || nums === null) return;
 8 
 9     // normal case
10     let left = 0;
11     let right = nums.length - 1;
12     let cur = 0;
13     while (cur <= right) {
14         if (nums[cur] === 0) {
15             swap(nums, cur, left);
16             cur++;
17             left++;
18         } else if (nums[cur] === 1) {
19             cur++;
20         } else {
21             swap(nums, cur, right);
22             right--;
23         }
24     }
25 };
26 
27 var swap = function(nums, i, j) {
28     let temp = nums[i];
29     nums[i] = nums[j];
30     nums[j] = temp;
31 };