LeetCode 1470. Shuffle the Array

Description

https://leetcode.com/problems/shuffle-the-array/

Given the array nums consisting of 2n elements in the form [x1,x2,...,xn,y1,y2,...,yn].

Return the array in the form [x1,y1,x2,y2,...,xn,yn].

Example 1:

Input: nums = [2,5,1,3,4,7], n = 3
Output: [2,3,5,4,1,7] 
Explanation: Since x1=2, x2=5, x3=1, y1=3, y2=4, y3=7 then the answer is [2,3,5,4,1,7].

Example 2:

Input: nums = [1,2,3,4,4,3,2,1], n = 4
Output: [1,4,2,3,3,2,4,1]

Example 3:

Input: nums = [1,1,2,2], n = 2
Output: [1,2,1,2]

Constraints:

• 1 <= n <= 500
• nums.length == 2n
• 1 <= nums[i] <= 10^3

Explanation

Two pointers, one from the beginning of the list, the other one from the n th position of the list.

Python Solution

class Solution:
    def shuffle(self, nums: List[int], n: int) -> List[int]:
        results = []
                
        j = n
        for i in range(0, n):
            results.append(nums[i])
            results.append(nums[j])
            j += 1
            
        return results

• Time complexity: O(N).
• Space complexity: O(N).