From 8d899dfe8f1d89d0afec2d005a9358af387251b0 Mon Sep 17 00:00:00 2001
From: Levy <golvwei@gmail.com>
Date: Sun, 28 Apr 2024 22:42:48 +0800
Subject: [PATCH] 0977: Squares of a sorted array

---
 0977-Squares_of_a_Sorted_Array/main.ts   | 58 ++++++++++++++++++++++++
 0977-Squares_of_a_Sorted_Array/readme.md | 21 +++++++++
 2 files changed, 79 insertions(+)
 create mode 100644 0977-Squares_of_a_Sorted_Array/main.ts
 create mode 100644 0977-Squares_of_a_Sorted_Array/readme.md

diff --git a/0977-Squares_of_a_Sorted_Array/main.ts b/0977-Squares_of_a_Sorted_Array/main.ts
new file mode 100644
index 0000000..c63c21c
--- /dev/null
+++ b/0977-Squares_of_a_Sorted_Array/main.ts
@@ -0,0 +1,58 @@
+// let nums = [-4, -1, 0, 3, 10];
+let nums = [-7, -3, 2, 3, 11];
+
+function sortedSquaresByMapping(nums: number[]): number[] {
+  return nums.map((i) => i * i).sort((a, b) => a - b);
+}
+
+function sortedSquaresFromTwoEnds(nums: number[]): number[] {
+  const ans = new Array(nums.length);
+  let left = 0,
+    right = nums.length - 1;
+
+  for (let i = nums.length - 1; i >= 0; i--) {
+    if (Math.abs(nums[left]) > Math.abs(nums[right])) {
+      ans[i] = nums[left] * nums[left];
+      left++;
+    } else {
+      ans[i] = nums[right] * nums[right];
+      right--;
+    }
+  }
+
+  return ans;
+}
+
+function sortedSquaresByUnshifting(nums: number[]): number[] {
+  const ans: number[] = [];
+  let left = 0,
+    right = nums.length - 1;
+
+  while (left <= right) {
+    if (Math.abs(nums[left]) > nums[right]) {
+      ans.unshift(nums[left] ** 2);
+      left++;
+    } else {
+      ans.unshift(nums[right] ** 2);
+      right--;
+    }
+  }
+
+  return ans;
+}
+
+console.time("sortedSquaresByMapping");
+let resultByMapping = sortedSquaresByMapping(nums);
+console.timeEnd("sortedSquaresByMapping");
+
+console.time("sortedSquaresFromTwoEnds");
+let resultFromTwoEnds = sortedSquaresFromTwoEnds(nums);
+console.timeEnd("sortedSquaresFromTwoEnds");
+
+console.time("sortedSquaresByUnshifting");
+let resultByUnshifting = sortedSquaresByUnshifting(nums);
+console.timeEnd("sortedSquaresByUnshifting");
+
+console.log(resultByUnshifting);
+console.log(resultByMapping);
+console.log(resultFromTwoEnds);
diff --git a/0977-Squares_of_a_Sorted_Array/readme.md b/0977-Squares_of_a_Sorted_Array/readme.md
new file mode 100644
index 0000000..1077e3f
--- /dev/null
+++ b/0977-Squares_of_a_Sorted_Array/readme.md
@@ -0,0 +1,21 @@
+# 977. Squares of a Sorted Array
+
+Given an integer array `nums` sorted in <b>non-decreasing</b> order, return <i>an array of <b>the squares of each number</b> sorted in non-decreasing order</i>.
+
+## Example 1:
+
+> <span style="color: white;">Input</span>: nums = [-4, -1, 0, 3, 10]<br>
+> <span style="color: white;">Output</span>: [0, 1, 9, 16, 100]<br>
+> <span style="color: white;">Explanation</span>: After squaring, the array becomes [16, 1, 0, 9, 100].<br>
+> After sorting, it becomes [0, 1, 9, 16, 100].
+
+## Example 2:
+
+> <span style="color: white;">Input</span>: nums = [-7, -3, 2, 3, 11]<br>
+> <span style="color: white;">Output</span>: [4, 9, 9, 49, 121]
+
+## Constraints:
+
+- 1 <= nums.length <= 10<sup>4</sup>
+- -10<sup>4</sup> <= nums[i] <= 10<sup>4</sup>
+- `nums` is sorted in <b>non-decreasing</b> order.