feat: add squares of a sorted array solution

Author: sandrig

README.md

@@ -2,13 +2,14 @@
 
 ## Easy
 
-| #   | Problem                                                                         | Solution                                                                                                   | Time   | Space  | Tag                    |
-| --- | ------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------- | ------ | ------ | ---------------------- |
-| 1   | [Two Sum](https://leetcode.com/problems/two-sum/)                               | [TypeScript](https://github.com/sandrig/leetcode/blob/master/typescript/src/twoSum/README.md)              | _O(n)_ | _O(n)_ | Array, Hash Table      |
-| 2   | [Move Zeroes](https://leetcode.com/problems/move-zeroes/)                       | [TypeScript](https://github.com/sandrig/leetcode/blob/master/typescript/src/moveZeroes/README.md)          | _O(n)_ | _O(1)_ | Array, Two Pointers    |
-| 3   | [Valid Palindrome](https://leetcode.com/problems/valid-palindrome/)             | [TypeScript](https://github.com/sandrig/leetcode/blob/master/typescript/src/validPalindrome/README.md)     | _O(n)_ | _O(n)_ | String, Two Pointers   |
-| 4   | [Summary Ranges](https://leetcode.com/problems/summary-ranges/)                 | [TypeScript](https://github.com/sandrig/leetcode/blob/master/typescript/src/summaryRanges/README.md)       | _O(n)_ | _O(n)_ | Array                  |
-| 5   | [Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/) | [TypeScript](https://github.com/sandrig/leetcode/blob/master/typescript/src/mergeTwoSortedLists/README.md) | _O(n)_ | _O(n)_ | Linked List, Recursion |
+| #   | Problem                                                                               | Solution                                                                                                     | Time   | Space  | Tag                          |
+| --- | ------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------ | ------ | ------ | ---------------------------- |
+| 1   | [Two Sum](https://leetcode.com/problems/two-sum/)                                     | [TypeScript](https://github.com/sandrig/leetcode/blob/master/typescript/src/twoSum/README.md)                | _O(n)_ | _O(n)_ | Array, Hash Table            |
+| 2   | [Move Zeroes](https://leetcode.com/problems/move-zeroes/)                             | [TypeScript](https://github.com/sandrig/leetcode/blob/master/typescript/src/moveZeroes/README.md)            | _O(n)_ | _O(1)_ | Array, Two Pointers          |
+| 3   | [Valid Palindrome](https://leetcode.com/problems/valid-palindrome/)                   | [TypeScript](https://github.com/sandrig/leetcode/blob/master/typescript/src/validPalindrome/README.md)       | _O(n)_ | _O(n)_ | String, Two Pointers         |
+| 4   | [Summary Ranges](https://leetcode.com/problems/summary-ranges/)                       | [TypeScript](https://github.com/sandrig/leetcode/blob/master/typescript/src/summaryRanges/README.md)         | _O(n)_ | _O(n)_ | Array                        |
+| 5   | [Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/)       | [TypeScript](https://github.com/sandrig/leetcode/blob/master/typescript/src/mergeTwoSortedLists/README.md)   | _O(n)_ | _O(n)_ | Linked List, Recursion       |
+| 6   | [Squares of a Sorted Array](https://leetcode.com/problems/squares-of-a-sorted-array/) | [TypeScript](https://github.com/sandrig/leetcode/blob/master/typescript/src/squaresOfaSortedArray/README.md) | _O(n)_ | _O(1)_ | Array, Two Pointers, Sorting |
 
 ## Medium
 

typescript/src/squaresOfaSortedArray/README.md

@@ -0,0 +1,53 @@
+# [Squares of a Sorted Array](https://leetcode.com/problems/squares-of-a-sorted-array/)
+
+## Description
+
+Given an integer array **nums** sorted in non-decreasing order, return an array of the squares of each number sorted in non-decreasing order.
+
+**Example 1:**
+
+```
+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].
+```
+
+**Example 2:**
+
+```
+Input: nums = [-7,-3,2,3,11]
+Output: [4,9,9,49,121]
+```
+
+## Solution
+
+```typescript
+function sortedSquares(nums: number[]): number[] {
+  const result: number[] = [];
+
+  let left = 0;
+  let right = nums.length - 1;
+
+  while (left <= right) {
+    const leftSquare = nums[left] * nums[left];
+    const rightSquare = nums[right] * nums[right];
+
+    if (leftSquare >= rightSquare) {
+      result.unshift(leftSquare);
+      left++;
+    } else {
+      result.unshift(rightSquare);
+      right--;
+    }
+  }
+
+  return result;
+}
+```
+
+## Complexity Analysis
+
+- Time complexity: _O(n)_
+
+- Space complexity: _O(1)_

typescript/src/squaresOfaSortedArray/sortedSquares.test.ts

@@ -0,0 +1,45 @@
+import { sortedSquares } from "./sortedSquares";
+
+describe("Squares of a Sorted Array", () => {
+  it("should return squares of sorted array when input contains positive and negative integers", () => {
+    const nums = [-4, -1, 0, 3, 10];
+    const expected = [0, 1, 9, 16, 100];
+    const result = sortedSquares(nums);
+    expect(result).toEqual(expected);
+  });
+
+  it("should return squares of sorted array when input contains all positive integers", () => {
+    const nums = [1, 2, 3, 4, 5];
+    const expected = [1, 4, 9, 16, 25];
+    const result = sortedSquares(nums);
+    expect(result).toEqual(expected);
+  });
+
+  it("should return squares of sorted array when input contains all negative integers", () => {
+    const nums = [-5, -4, -3, -2, -1];
+    const expected = [1, 4, 9, 16, 25];
+    const result = sortedSquares(nums);
+    expect(result).toEqual(expected);
+  });
+
+  it("should return squares of sorted array when input contains a mix of positive and negative integers", () => {
+    const nums = [-7, -3, -1, 4, 5, 9];
+    const expected = [1, 9, 16, 25, 49, 81];
+    const result = sortedSquares(nums);
+    expect(result).toEqual(expected);
+  });
+
+  it("should return squares of sorted array when input contains a single element", () => {
+    const nums = [0];
+    const expected = [0];
+    const result = sortedSquares(nums);
+    expect(result).toEqual(expected);
+  });
+
+  it("should return an empty array when input is an empty array", () => {
+    const nums: number[] = [];
+    const expected: number[] = [];
+    const result = sortedSquares(nums);
+    expect(result).toEqual(expected);
+  });
+});

typescript/src/squaresOfaSortedArray/sortedSquares.ts

@@ -0,0 +1,21 @@
+export function sortedSquares(nums: number[]): number[] {
+  const result: number[] = [];
+
+  let left = 0;
+  let right = nums.length - 1;
+
+  while (left <= right) {
+    const leftSquare = nums[left] * nums[left];
+    const rightSquare = nums[right] * nums[right];
+
+    if (leftSquare >= rightSquare) {
+      result.unshift(leftSquare);
+      left++;
+    } else {
+      result.unshift(rightSquare);
+      right--;
+    }
+  }
+
+  return result;
+}