add 977 solution

Author: BrianRuizy

977 - Squares Of A Sorted Array.md

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+# 977 - Squares Of A Sorted Array
+
+Difficulty: easy
+Done: No
+Last edited: February 17, 2022 12:47 PM
+Topic: two pointers
+
+## 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*.
+
+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]
+
+```
+
+Constraints:
+
+- `1 <= nums.length <= 104`
+- `104 <= nums[i] <= 104`
+- `nums` is sorted in **non-decreasing** order.
+
+## Solution
+
+lorem ipsum
+
+## Whiteboard
+
+[http://excalidraw.com](http://excalidraw.com)
+
+## Code
+
+```python
+class Solution:
+    def sortedSquares(self, nums: List[int]) -> List[int]:
+        return sorted([x**2 for x in nums])
+```
+
+using built-in sorted
+
+```python
+class Solution:
+    def sortedSquares(self, nums: List[int]) -> List[int]:
+        left, right = 0, len(nums)-1
+
+        while left <= right:
+            
+            max_abs = max(nums[left:], key=abs)
+            
+            nums.insert(0, nums.pop(nums.index(max_abs)))
+            nums[0] = nums[0]**2
+            left += 1
+        
+        return nums
+```
+
+custom 2 pointer approach

977.py

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+class Solution:
+    def sortedSquares(self, nums):
+        left, right = 0, len(nums)-1
+
+        stack = []
+
+        while left <= right:
+            max_abs = max(nums, key=abs)
+            nums.remove(max_abs)
+            stack.insert(0, abs(max_abs)**2)
+            left += 1
+        
+        return stack
+
+
+if __name__ == '__main__':
+    s = Solution()
+    s.sortedSquares(nums = [-3, -3, 0,0, 1, 10])