1 - Easy - Shuffle an Array

打乱一个没有重复元素的数组。

示例:

// 以数字集合 1, 2 和 3 初始化数组。
int[] nums = {1,2,3};
Solution solution = new Solution(nums);

// 打乱数组 [1,2,3] 并返回结果。任何 [1,2,3]的排列返回的概率应该相同。
solution.shuffle();

// 重设数组到它的初始状态[1,2,3]。
solution.reset();

// 随机返回数组[1,2,3]打乱后的结果。
solution.shuffle();

class Solution:

    def __init__(self, nums):
        """
        :type nums: List[int]
        """
        self.nums = nums
        self.backup = nums[:]
        self.n = len(nums)
        

    def reset(self):
        """
        Resets the array to its original configuration and return it.
        :rtype: List[int]
        """
        self.nums = self.backup
        return self.nums
        

    def shuffle(self):
        """
        Returns a random shuffling of the array.
        :rtype: List[int]
        """
        import random
        temp = self.nums
        res = []
        for _ in range(self.n):
            cur = random.randint(0, len(temp)-1)
            res.append(temp[cur])
            temp = temp[:cur] + temp[cur+1:]
        self.nums = res
        return self.nums
        # random.shuffle(self.array)
        # return self.array


# Your Solution object will be instantiated and called as such:
# obj = Solution(nums)
# param_1 = obj.reset()
# param_2 = obj.shuffle()