384.

Shuffle an Array

Medium

Given an integer array nums, design an algorithm to randomly shuffle the array. Implement the Solution class: Solution(int[] nums) Initializes the object with the integer array nums. int[] reset() Resets the array to its original configuration and returns it. int[] shuffle() Returns a random shuffling of the array. Example 1: Input ["Solution", "shuffle", "reset", "shuffle"] [[[1, 2, 3]], [], [], []] Output [null, [3, 1, 2], [1, 2, 3], [1, 3, 2]] Explanation Solution solution = new Solution([1, 2, 3]); solution.shuffle(); // Shuffle the array [1,2,3] and return its result. Any permutation of [1,2,3] must be equally likely to be returned. Example: return [3, 1, 2] solution.reset(); // Resets the array back to its original configuration [1,2,3]. Return [1, 2, 3] solution.shuffle(); // Returns the random shuffling of array [1,2,3]. Example: return [1, 3, 2] Constraints: 1 <= nums.length <= 200 -106 <= nums[i] <= 106 All the elements of nums are unique. At most 5 * 104 calls will be made to reset and shuffle.