> ## Documentation Index
> Fetch the complete documentation index at: https://leetcode-py.wisl.dev/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> leetcode-py is a Python LeetCode practice environment generator with one CLI: lcpy. It is not a service or platform.
> Each problem is a directory under leetcode/ with README.md, solution.py, test_solution.py, helpers.py, and playground.ipynb. lcpy gen creates them from JSON templates bundled with the package.
> Examples are backed by tests; copy them verbatim.

# Squares of a Sorted Array Python Solution

> Tested Python solution for LeetCode 977 with 14 pytest cases. Generate a practice environment with lcpy.

LeetCode 977, Easy. Topics: Array, Two Pointers, Sorting. [View on LeetCode](https://leetcode.com/problems/squares-of-a-sorted-array/description/).

Generate this problem as a practice environment: tested reference solution, 14 [parametrized pytest cases](/practice/testing), and a playground notebook:

```bash theme={"theme":{"light":"github-light","dark":"github-dark"}}
lcpy gen -n 977   # by problem number
lcpy gen -s squares_of_a_sorted_array   # by problem name
```

## Problem

Given an integer array `nums` sorted in non-decreasing order, return *an array of the squares of each number* sorted in non-decreasing order.

### Examples

```
Input: nums = [-4,-1,0,3,10]
Output: [0,1,9,16,100]

Explanation: After squaring, the array becomes [16,1,0,9,100].
After sorting, it becomes [0,1,9,16,100].
```

```
Input: nums = [-7,-3,2,3,11]
Output: [4,9,9,49,121]
```

### Constraints

* `1 <= nums.length <= 10^4`
* `-10^4 <= nums[i] <= 10^4`
* `nums` is sorted in non-decreasing order.

**Follow up:** Squaring each element and sorting the new array is very trivial, could you find an `O(n)` solution using a different approach?

## Solution

Reference implementation from [solution.py on GitHub](https://github.com/wislertt/leetcode-py/blob/main/leetcode/squares_of_a_sorted_array/solution.py), full suite in [test\_solution.py](https://github.com/wislertt/leetcode-py/blob/main/leetcode/squares_of_a_sorted_array/test_solution.py):

```python theme={"theme":{"light":"github-light","dark":"github-dark"}}
class Solution:
    # Time: O(n)
    # Space: O(n)
    def sorted_squares(self, nums: list[int]) -> list[int]:
        result: list[int] = [0] * len(nums)
        left, right = 0, len(nums) - 1
        index = len(nums) - 1
        while left <= right:
            if abs(nums[left]) > abs(nums[right]):
                result[index] = nums[left] * nums[left]
                left += 1
            else:
                result[index] = nums[right] * nums[right]
                right -= 1
            index -= 1
        return result
```

## Complexity

| Time | Space |
| ---- | ----- |
| O(n) | O(n)  |

## Tags

[Grind](/catalog/grind), [NeetCode All](/catalog/neetcode).