# LeetCode: 384. 打乱数组¶

## 1、题目描述¶

// 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();


## 2、解题思路¶

• 首先，我们保存原来的数组，在重置的时候，直接返回
• 然后，使用交换的思路，对每一个数，求解他想要取得位置，使用一个随机数，随机生成

​ 当然，也可以直接使用random库中自带的shuffle函数

class Solution:

def __init__(self, nums):
"""
:type nums: List[int]
"""

self.origin = nums

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

def shuffle(self):
"""
Returns a random shuffling of the array.
:rtype: List[int]
"""
cur = self.origin.copy()
length = len(self.origin)
for i in range(length):
pos = random.randint(0, length - 1)
cur[i], cur[pos] = cur[pos], cur[i]
return cur

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

class Solution:

def __init__(self, nums):
"""
:type nums: List[int]
"""

self.origin = nums

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

def shuffle(self):
"""
Returns a random shuffling of the array.
:rtype: List[int]
"""
cur = self.origin.copy()
random.shuffle(cur)
return cur

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