【LeetCode】648.Replace Words(Medium)解题报告

【LeetCode】648.Replace Words(Medium)解题报告

题目地址：https://leetcode.com/problems/replace-words/description/

题目描述：

  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.

Note:
1. The input will only have lower-case letters.
2. 1 <= dict words number <= 1000
3. 1 <= sentence words number <= 1000
4. 1 <= root length <= 100
5. 1 <= sentence words length <= 1000

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

Solution:

class Solution {
public String replaceWords(List<String> dict, String sentence) {
Set<String> set = new HashSet<>(dict);
StringBuilder sb = new StringBuilder();
String[] words = sentence.split(" ");
for(int i=0;i<words.length;i++){
for(int j=0;j<words[i].length();j++){
String root = words[i].substring(0,j);
if(set.contains(root)){
words[i]=root;
}

}
sb.append(words[i]+" ");

}
return sb.substring(0,sb.length()-1);
}
}

Date：2017年12月12日