Leetcode#139. Word Break
ProblemGiven a string s and a dictionary of strings wordDict, return true if s can be segmented into a space-separated sequence of one or more dictionary words.
Note that the same word in the dictionary may be reused multiple times in the segmentation.
Example 1:
1234Input: s = "leetcode", wordDict = ["leet","code"]Output: trueExplanation: Return true because "leetcode" can be segmented as "leet code".
Example 2:
12345Input: s = "applepenap ...
How to create a trie in Python
How to create a trie in PythonTrieTrie 像一顆特別的樹，每個節點都是一個字母，從根節點到葉節點的路徑上的字母連起來就是一個單詞。
用途搜尋提示，比如輸入一個單詞，自動提示可能的後續單詞。
優點搜尋效率高，不用像哈希表一樣，需要計算哈希值，直接根據單詞的每個字母，一層一層的往下搜尋即可。
缺點空間消耗大，因為每個節點都需要存儲子節點的指針，當單詞數量很多時，需要的空間就很大。
建立 Trie1234567891011121314151617181920212223242526272829303132class TrieNode: def __init__(self): self.children = {} self.is_word = Falseclass Trie: def __init__(self): self.root = TrieNode() def insert(self, word): node = self.root f ...
Leetcode#212. Word Search II
簡易leetcode79
ProblemGiven an m x n board of characters and a list of strings words, return all words on the board.
Each word must be constructed from letters of sequentially adjacent cells, where adjacent cells are horizontally or vertically neighboring. The same letter cell may not be used more than once in a word.
Example 1:
!https://assets.leetcode.com/uploads/2020/11/07/search1.jpg
123Input: board = [["o","a","a","n"],["e","t",&quo ...