Leetcode Question 384 'Shuffle an Array' in Java

Given an integer array nums, design an algorithm to randomly shuffle the array. All permutations of the array should be equally likely as a result of the shuffling.

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]);
// Any permutation of [1,2,3] must be equally likely to be returned.
// Example: return [3, 1, 2]