LeetCode 384. Shuffle an Array

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();

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What a pity for the bug:

import random
class Solution:

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

    def reset(self) -> List[int]:
        """
        Resets the array to its original configuration and return it.
        """
        return list(self.nums)
        

    def shuffle(self) -> List[int]:
        """
        Returns a random shuffling of the array.
        """
        res = list(self.nums)
        l = len(res)
        for i in range(l-1):
            j = random.randint(i,l-1) #bug1: random.randint(i+1,l-1)
            res[i],res[j] = res[j],res[i]
        return res
        
# Your Solution object will be instantiated and called as such:
# obj = Solution(nums)
# param_1 = obj.reset()
# param_2 = obj.shuffle()