[LeetCode] 648. Replace Words

- Problem

648. Replace Words

In English, we have a concept called root, which can be followed by some other word to form another longer word - let's call this word successor. For example, when the root "an" is followed by the successor word "other", we can form a new word "another".

Given a dictionary consisting of many roots and a sentence consisting of words separated by spaces, replace all the successors in the sentence with the root forming it. If a successor can be replaced by more than one root, replace it with the root that has the shortest length.

Return the sentence after the replacement.

Example 1:

Input: dictionary = ["cat","bat","rat"], sentence = "the cattle was rattled by the battery"
Output: "the cat was rat by the bat"

Example 2:

Input: dictionary = ["a","b","c"], sentence = "aadsfasf absbs bbab cadsfafs"
Output: "a a b c"

Constraints:

• 1 <= dictionary.length <= 1000
• 1 <= dictionary[i].length <= 100
• dictionary[i] consists of only lower-case letters.
• 1 <= sentence.length <= 10^6
• sentence consists of only lower-case letters and spaces.
• The number of words in sentence is in the range [1, 1000]
• The length of each word in sentence is in the range [1, 1000]
• Every two consecutive words in sentence will be separated by exactly one space.
• sentence does not have leading or trailing spaces.

- 내 풀이

class TrieNode:
    def __init__(self):
        self.children = {}
        self.word = ""
        
class Trie:
    def __init__(self):
        self.root = TrieNode()
        
    def add(self, word):
        curr = self.root
        
        for w in word:
            if w not in curr.children:
                curr.children[w] = TrieNode()
            curr = curr.children[w]
        
        curr.word = word
    
    def search(self, word):
        curr = self.root
        
        for w in word:
            if w not in curr.children:
                return False
            
            curr = curr.children[w]
            
            if curr.word:
                return curr.word
        
        return False
        
        

class Solution:
    def replaceWords(self, dictionary: List[str], sentence: str) -> str:
        trie = Trie()
        answer = []
        
        for word in dictionary:
            trie.add(word)
            
        for word in sentence.split():
            find_word = trie.search(word)
            
            if find_word:
                answer.append(find_word)
            else:
                answer.append(word)
        
        return " ".join(answer)

- 결과