Created
August 14, 2024 21:12
-
-
Save codecakes/ed5db0b453794f9f3c6b676cc5ec93aa to your computer and use it in GitHub Desktop.
Given a string s and a dictionary of strings wordDict, add spaces in s to construct a sentence where each word is a valid dictionary word.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| """ | |
| Input | |
| s = | |
| "pineapplepenapple" | |
| wordDict = | |
| ["apple","pen","applepen","pine","pineapple"] | |
| """ | |
| # This works | |
| class Solution: | |
| def wordBreak(self, s: str, wordDict: List[str]) -> List[str]: | |
| res = [] | |
| wordSet = set(wordDict) | |
| def backtrack(s, curr_word, res): | |
| if not s: | |
| res += [' '.join(curr_word)] | |
| return | |
| substr = "" | |
| for idx, char in enumerate(s): | |
| substr += char | |
| if substr in wordSet: | |
| curr_word += [substr] | |
| backtrack(s[idx+1:], curr_word, res) | |
| curr_word.pop() | |
| backtrack(s, [], res) | |
| return res | |
| # So does this, but faster and better | |
| import functools | |
| class Solution: | |
| def wordBreak(self, s: str, wordDict: List[str]) -> List[str]: | |
| wordDict = set(wordDict) | |
| @functools.cache | |
| def backtrack(s): | |
| if not s: | |
| return [""] | |
| substr = "" | |
| res = [] | |
| for idx, char in enumerate(s): | |
| curr_word = [] | |
| substr += char | |
| if substr in wordDict: | |
| for rest_statement in backtrack(s[idx+1:]): | |
| if rest_statement: | |
| res += [f"{substr} {rest_statement}"] | |
| else: | |
| res += [substr] | |
| return res or [] | |
| res = backtrack(s) | |
| return res | |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment