Week4 (Apr 8) - HackMD

# Week4 (Apr 8) ## 78. Subsets ### Question Given an integer array $nums$ of **unique** elements, return all possible subsets (the power set). The solution set **must not** contain duplicate subsets. Return the solution in **any order**. ### Hand in homework before Saturday. :::success [Woody的作業](https://github.com/woodycatliu/leetcode/blob/main/0078_Subsets/78.swift) [Roger的作業](https://github.com/GametreeRoger/LeetCode/blob/main/LeetCode78.playground/Contents.swift) [Allen的作業](https://github.com/allen870619/leetcode_practice/blob/main/1-500/78.%20Subsets.playground/Contents.swift) [xander的作業](https://github.com/Takumi47/30Plus/blob/main/30Plus/Problems/78_Subsets.swift) ...`Continue filling by yourself` ::: ## 430. Flatten a Multilevel Doubly Linked List ### Question You are given a doubly linked list, which contains nodes that have a next pointer, a previous pointer, and an additional **child pointer**. This child pointer may or may not point to a separate doubly linked list, also containing these special nodes. These child lists may have one or more children of their own, and so on, to produce a **multilevel data structure** as shown in the example below. Given the $head$ of the first level of the list, **flatten** the list so that all the nodes appear in a single-level, doubly linked list. Let $curr$ be a node with a child list. The nodes in the child list should appear **after** $curr$ and **before** $curr.next$ in the flattened list. Return *the* $head$ *of the flattened list*. *The nodes in the list must have **all** of their child pointers set to* $null$. ### Hand in homework before Saturday. :::success [Woody的作業](https://github.com/woodycatliu/leetcode/blob/main/0430_FlattenAMultilevelDoublyLinkedList/430.swift) [Roger的作業](https://github.com/GametreeRoger/LeetCode/blob/main/LeetCode430.playground/Contents.swift) [Allen的作業](https://github.com/allen870619/leetcode_practice/blob/main/1-500/430.%20Flatten%20a%20Multilevel%20Doubly%20Linked%20List.playground/Contents.swift) [xander的作業](https://github.com/Takumi47/30Plus/blob/main/30Plus/Problems/430_FlattenAMultilevelDoublyLinkedList.swift) ...`Continue filling by yourself` :::