384.打乱数组.js

/*
 * @lc app=leetcode.cn id=384 lang=javascript
 *
 * [384] 打乱数组
 */

// @lc code=start
/**
 * @param {number[]} nums
 */
var Solution = function(nums) {
  this.nums = nums;
};

/**
 * Resets the array to its original configuration and return it.
 * @return {number[]}
 */
Solution.prototype.reset = function() {
  return this.nums;
};

/**
 * Returns a random shuffling of the array.
 * @return {number[]}
 */
Solution.prototype.shuffle = function() {
  // Fisher-Yates 洗牌算法
  let arr = [...this.nums];

  let i = arr.length;
  let j = 0;
  while (i) {
    j = Math.floor(Math.random() * i--);
    [arr[i], arr[j]] = [arr[j], arr[i]];
  }

  return arr;
};

/**
 * Your Solution object will be instantiated and called as such:
 * var obj = new Solution(nums)
 * var param_1 = obj.reset()
 * var param_2 = obj.shuffle()
 */
// @lc code=end