4. Median of Two Sorted Arrays
4. Median of Two Sorted Arrays
這個題目直覺的解法很簡單，做法也很多種，因為題目的邏輯很簡單，就是要找到中位數。
Classic
16. 3Sum Closest
16. 3Sum Closest
516. Longest Palindromic Subsequence
516. Longest Palindromic Subsequence
這一題和 647. Palindromic Substrings 很像，只是其中的差異是一個問的是「
1490. Clone N-ary Tree
1490. Clone N-ary Tree
這個題目是樹，題目要考察是否可以寫出遍歷整棵樹的程式碼，類似的題目是 133. Clone Graph
315. Count of Smaller Numbers After Self
315. Count of Smaller Numbers After Self
class BinaryIndexedTree:
def
227. Basic Calculator II
227. Basic Calculator II
放進去 stack 的數字，如果都是正、負數的話，就可以直接加總，
188. Best Time to Buy and Sell Stock IV
188. Best Time to Buy and Sell Stock IV
自頂向下
1136. Parallel Courses
1136. Parallel Courses
這個題目是 207. Course Schedule 和 210. Course
369. Plus One Linked List
369. Plus One Linked List
# Definition for singly-linked list.
# class
303. Range Sum Query - Immutable
303. Range Sum Query - Immutable
class NumArray:
def __init_