LeetCode: Shuffle an Array Solution

Approach

Use Fisher–Yates shuffle algorithm

With every i from 0 to N-1 (N is length of the array)

• get random integer j in range [i, N-1]
• swap array[i] and array[j]

Implementation

1/**
2 * @param {number[]} nums
3 */
4var Solution = function (nums) {
5  this.orignalNums = [...nums]
6  this.nums = [...nums]
7}
8
9/**
10 * Resets the array to its original configuration and return it.
11 * @return {number[]}
12 */
13Solution.prototype.reset = function () {
14  this.nums = [...this.orignalNums]
15  return this.nums
16}
17
18/**
19 * Returns a random shuffling of the array.
20 * @return {number[]}
21 */
22Solution.prototype.shuffle = function () {
23  for (let i = 0; i < this.nums.length; i++) {
24    const j = getRandomInt(i, this.nums.length)
25    ;[this.nums[i], this.nums[j]] = [this.nums[j], this.nums[i]]
26  }
27  return this.nums
28}
29
30function getRandomInt(min, max) {
31  return Math.floor(Math.random() * (max - min) + min)
32}
33
34/**
35 * Your Solution object will be instantiated and called as such:
36 * var obj = new Solution(nums)
37 * var param_1 = obj.reset()
38 * var param_2 = obj.shuffle()
39 */