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leetcode384: shuffle an array 2. Analysis 3. Solution(s)

admin 11月 12, 2020 0

Shuffle a set of numbers without duplicates.

Example:

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();

2. Analysis

Using python permutations and combinations package(itertools) or random package(shuffle)

3. Solution(s)

Permutations:

import itertools
import random
class (object):
    def __init__(self, nums):
        """
        :type nums: List[int]
        :type size: int
        """
        self.array = nums
    def reset(self):
        """
        Resets the array to its original configuration and return it.
        :rtype: List[int]
        """
        return self.array
    def shuffle(self):
        """
        Returns a random shuffling of the array.
        :rtype: List[int]
        """
        reslist = list(itertools.permutations(self.array, len(self.array)))
        print reslist
        return reslist[random.randint(0, len(reslist)-1)]
# Your Solution object will be instantiated and called as such:
# obj = Solution(nums)
# param_1 = obj.reset()
# param_2 = obj.shuffle()

random shuffle:

import random
class (object):
    def __init__(self, nums):
        """
        :type nums: List[int]
        :type size: int
        """
        self.array_original = self.array = nums
    def reset(self):
        """
        Resets the array to its original configuration and return it.
        :rtype: List[int]
        """
        self.array = self.array_original
        return self.array
    def shuffle(self):
        """
        Returns a random shuffling of the array.
        :rtype: List[int]
        """
        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()