0
点赞
收藏
分享

微信扫一扫

384. Shuffle an Array

Sikj_6590 2022-08-03 阅读 28


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();

class Solution {
private int[] original;
private Random rng = new Random();
private int[] copy;
private int num;
public Solution(int[] nums) {
original = nums;
copy=original.clone();
num=original.length;
}

/** Resets the array to its original configuration and return it. */
public int[] reset() {
return original;
}

/** Returns a random shuffling of the array. */
public int[] shuffle() {
int n = num;
while(n>1) {
n--;
int k = rng.nextInt(n + 1);
int value = copy[k];
copy[k] = copy[n];
copy[n] = value;
}
return copy;
}
}

/**
* 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();
*/


举报

相关推荐

0 条评论