Shuffle an Array

Shuffle a set of numbers without duplicates.

Example:

// Init an array with set 1, 2, and 3.
int[] nums = {1,2,3};
Solution solution = new Solution(nums);

// Shuffle the array [1,2,3] and return its result. Any permutation of [1,2,3] must equally likely to be returned.
solution.shuffle();

// Resets the array back to its original configuration [1,2,3].
solution.reset();

// Returns the random shuffling of array [1,2,3].
solution.shuffle();

get random int o(1), clone int array o(n), swap o(1),shuffle o(n)

class Solution {
    private int[] array;
    private int[] original;
    public Solution(int[] nums) {
        this.array = nums;
        this.original = nums.clone();
    }
    
    /** Resets the array to its original configuration and return it. */
    public int[] reset() {
        array = original;
        original = original.clone();
        return original;
    }
    
    
    public int getRandom(int min, int max){
        Random r = new Random();
        
        return r.nextInt(max-min)+min;
    }
    
    public void swapAt(int i, int j){
        int tmp = array[i];
        array[i] = array[j];
        array[j] = tmp;
    }
    /** Returns a random shuffling of the array. */
    public int[] shuffle() {
        for(int i = 0; i <array.length; i++ ){
            swapAt(i, getRandom(i,array.length));
        }
        
        return array;
    }
}

/**
 * Your Solution object will be instantiated and called as such:
 * Solution obj = new Solution(nums);
 * int[] param_1 = obj.reset();
 * int[] param_2 = obj.shuffle();
 */