106. Construct Binary Tree from Inorder and Postorder Traversal
106. Construct Binary Tree from Inorder and Postorder Traversal
postorder
Gary Lai
124. Binary Tree Maximum Path Sum
124. Binary Tree Maximum Path Sum
這一題是後序遍歷的經典題目，後序遍歷的精神就是先將子樹的問題全部解決，再開始處理跟節點的問題，這一題要怎麼想到的確是屬於困難的題型。
437. Path Sum III
437. Path Sum III
更難的樹的遍歷加上回溯法。
# Definition for a binary tree
286. Walls and Gates
286. Walls and Gates
題目給定一個矩陣，矩陣內有標記了牆與門，剩餘的點被標註成一個無限大的數值，意義為可以行走的點，要求把這些矩陣中除了門與牆以外的點，以該點到達附近最近的門的距離為何？
590. N-ary Tree Postorder Traversal
590. N-ary Tree Postorder Traversal
"""
# Definition for
144. Binary Tree Preorder Traversal
144. Binary Tree Preorder Traversal
# Definition for a binary tree
297. Serialize and Deserialize Binary Tree
297. Serialize and Deserialize Binary Tree
這一題可以透過 536. Construct Binary
677. Map Sum Pairs
667. Map Sum Pairs
class TrieNode:
def __init__(self, val
588. Design In-Memory File System
588. Design In-Memory File System
class TrieNode:
def __init__(self)
19. Remove Nth Node From End of List
19. Remove Nth Node From End of List
這一題我的第一個想法是我先走一趟算出整個 Linked