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ProblemGiven a n * n matrix grid of 0's and 1's only. We want to represent grid with a Quad-Tree. Return the root of the Quad-Tree representing grid. A Quad-Tree is a tree data structure in which each internal node has exactly four children. Besides, each node has two attributes: val: True if the node represents a grid of 1’s or False if the node represents a grid of 0’s. Notice that you can assign the val to True or False when isLeaf is False, and both are accepted in the answer. isLea ...

ProblemGiven the head of a linked list, return the list after sorting it in ascending order. Example 1: 123Input: head = [4,2,1,3]Output: [1,2,3,4] Example 2: 123Input: head = [-1,5,3,4,0]Output: [-1,0,3,4,5] Example 3: 12Input: head = []Output: [] Solve1234567891011121314151617181920212223242526272829303132333435363738394041424344class Solution: def sortList(self, head: Optional[ListNode]) -> Optional[ListNode]: # 沒有 或只只有一個 代表已經排好了 if not head or not head.next: ...