g0301_0400.s0384_shuffle_an_array

Class Solution

java.lang.Object

g0301_0400.s0384_shuffle_an_array.Solution

public class Solution
extends Object

384 - Shuffle an Array.

Medium

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]); 
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 in total will be made to reset and shuffle.

Constructor Summary

Constructors

Constructor and Description
Solution(int[] nums)

Method Summary

Modifier and Type	Method and Description
int[]	reset()
int[]	shuffle()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution(int[] nums)

Method Detail

reset

public int[] reset()

shuffle

public int[] shuffle()