LeetCode 算法題 – Replace Words

首先介紹幾個概念 rootsuccessorroot 後面拼接一個單詞可以形成一個長單詞,該長單詞被稱為 successor。舉個例子, rootan, 拼接單詞 other 形成 anotheranother 就是 successor

現在給出一個包含多個 root 的字典數組和一個句子。請將句子中的 successor 替換成 root。 如果 successor 有多個 root, 則用最短的 root 替換。


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

Now, given a dictionary consisting of many roots and a sentence. You need to replace all the successor in the sentence with the root forming it. If a successor has many roots can form it, replace it with the root with the shortest length.

You need to output the sentence after the replacement.

Example 1:

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


  • The input will only have lower-case letters
  • 1 <= dict words number <= 1000
  • 1 <= sentence words number <= 1000
  • 1 <= root length <= 100
  • 1 <= sentence words length <= 1000


如題所述,目的是將句子中的單詞(也就是 successor)用其 root 替換。

  1. 根據空格將句子分離為一個單詞數組
  2. 將單詞逐個尋找其 root,有則替換,無則忽略
  3. 將替換後的單詞數組,用空格拼接成新句子返回

另外需要注意的是,要找到最短的 root 進行替換。


func replaceWords(dict []string, sentence string) string {
    words := strings.Split(sentence, " ")

    for i := 0; i < len(words); i++ {
        for _, v := range dict {
            if len(words[i]) >= len(v) && words[i][:len(v)] == v {
                // in order to find the shortest root, doesn't break on here
                words[i] = v

    return strings.Join(words, " ")