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Abhishek Chaudhary
Abhishek Chaudhary

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Shuffle an Array

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 <= 50
  • -106 <= nums[i] <= 106
  • All the elements of nums are unique.
  • At most 104 calls in total will be made to reset and shuffle.

SOLUTION:

import random

class Solution:

    def __init__(self, nums: List[int]):
        self.nums = nums

    def reset(self) -> List[int]:
        return self.nums

    def shuffle(self) -> List[int]:
        return sorted(self.nums, key = lambda x: random.random())


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