2025-09-22 19:06

Status: adult

Tags: leetcode leetcode-easy two-pointers google Leetcode

Squares of a Sorted Array

Code

import heapq
 
class Solution(object):
    def sortedSquares(self, nums):
        """
        :type nums: List[int]
        :rtype: List[int]
        """
 
        res = []
        l, r = 0, len(nums) - 1
 
        while l <= r:
            if abs(nums[r]) > abs(nums[l]):
                res.append(nums[r] ** 2)
                r -= 1
                
            else:
                res.append(nums[l] ** 2)
                l += 1
        
        return res[::-1]

Explanation

1. Since this is sorted in increasing order, we can use two pointers, one on the left and right.
2. We check if the abs(nums[r]) > abs(nums[l]), and move the right pointer to the left and vice versa for the left.
3. The result list will be in decreasing order so all we need to do is reverse it at the end

References

Greg Hogg