LeetCode 384 Shuffle An Array - Medium

384. Shuffle An Array — Medium

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Problem

384. Shuffle an Array -- Medium

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();

Solution

class Solution:
    def __init__(self, nums):
        self.array = nums
 
    def reset(self):
 
        return self.array
 
    def shuffle(self):
        # must make a new copy first!!! because this will generate a new array without modifying the original
        res = self.array[:]
        for i in range(len(self.array)):
            swap_idx = random.randrange(i, len(self.array))
            res[i], res[swap_idx] = res[swap_idx], res[i]
        return res