648. 单词替换 #

问题描述#

在英语中，我们有一个叫做 词根(root)的概念，它可以跟着其他一些词组成另一个较长的单词——我们称这个词为 继承词(successor)。例如，词根an，跟随着单词 other(其他)，可以形成新的单词 another(另一个)。

现在，给定一个由许多词根组成的词典和一个句子。你需要将句子中的所有继承词用词根替换掉。如果继承词有许多可以形成它的词根，则用最短的词根替换它。

你需要输出替换之后的句子。

示例 1：
输入：dictionary = ["cat","bat","rat"], sentence = "the cattle was rattled by the battery"
输出："the cat was rat by the bat"
示例 2：
输入：dictionary = ["a","b","c"], sentence = "aadsfasf absbs bbab cadsfafs"
输出："a a b c"
示例 3：
输入：dictionary = ["a", "aa", "aaa", "aaaa"], sentence = "a aa a aaaa aaa aaa aaa aaaaaa bbb baba ababa"
输出："a a a a a a a a bbb baba a"
示例 4：
输入：dictionary = ["catt","cat","bat","rat"], sentence = "the cattle was rattled by the battery"
输出："the cat was rat by the bat"
示例 5：
输入：dictionary = ["ac","ab"], sentence = "it is abnormal that this solution is accepted"
输出："it is ab that this solution is ac"
提示：

1 <= dictionary.length <= 1000

1 <= dictionary[i].length <= 100

dictionary[i] 仅由小写字母组成。

1 <= sentence.length <= 10^6

sentence 仅由小写字母和空格组成。

sentence 中单词的总量在范围 [1, 1000] 内。

sentence 中每个单词的长度在范围 [1, 1000] 内。

sentence 中单词之间由一个空格隔开。

sentence 没有前导或尾随空格。

解题思路#

字典树。

class Trie:
    def __init__(self):
        self.root = {}

    def insert(self, word: str) -> None:
        p = self.root
        for c in word:
            if c not in p:
                p[c] = {}
            p = p[c]
        p["$"] = ""

    def search(self, word: str):
        p = self.root
        ret = []
        for c in word:
            if c not in p:
                return word
            ret.append(c)
            p = p[c]
            if "$" in p:
                break
        return "".join(ret)


class Solution:
    def replaceWords(self, dictionary: List[str], sentence: str) -> str:
        trie = Trie()
        for word in dictionary:
            trie.insert(word)
        s = sentence.split()
        ans = []
        for word in s:
            ans.append(trie.search(word))
        return " ".join(ans)

# solve = Solution().replaceWords

# dictionary = ["cat","bat","rat"]
# sentence = "the cattle was rattled by the battery"
# ans = "the cat was rat by the bat"
# assert solve(dictionary, sentence) == ans

# dictionary = ["a","b","c"]
# sentence = "aadsfasf absbs bbab cadsfafs"
# ans = "a a b c"
# assert solve(dictionary, sentence) == ans

# dictionary = ["a", "aa", "aaa", "aaaa"]
# sentence = "a aa a aaaa aaa aaa aaa aaaaaa bbb baba ababa"
# ans = "a a a a a a a a bbb baba a"
# assert solve(dictionary, sentence) == ans

# dictionary = ["catt","cat","bat","rat"]
# sentence = "the cattle was rattled by the battery"
# ans = "the cat was rat by the bat"
# assert solve(dictionary, sentence) == ans

# dictionary = ["ac","ab"]
# sentence = "it is abnormal that this solution is accepted"
# ans = "it is ab that this solution is ac"
# assert solve(dictionary, sentence) == ans

648. 单词替换#

问题描述#

解题思路#

648. 单词替换 #