Concatenated Words_concatenated-words java 解法-优快云博客

本文链接：https://blog.youkuaiyun.com/sinat_28088761/article/details/68926711

本文介绍了一种算法，用于从给定的不含重复单词的列表中找出所有由至少两个更短单词组成的组合词。通过示例说明了如何使用该算法，并提供了Java实现代码。

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Given a list of words (without duplicates), please write a program that returns all concatenated words in the given list of words.

A concatenated word is defined as a string that is comprised entirely of at least two shorter words in the given array.

Example:

Input: ["cat","cats","catsdogcats","dog","dogcatsdog","hippopotamuses","rat","ratcatdogcat"]

Output: ["catsdogcats","dogcatsdog","ratcatdogcat"]

Explanation: "catsdogcats" can be concatenated by "cats", "dog" and "cats"; 
 "dogcatsdog" can be concatenated by "dog", "cats" and "dog"; 
"ratcatdogcat" can be concatenated by "rat", "cat", "dog" and "cat".

Java代码:

public static List<String> findAllConcatenatedWordsInADict(String[] words) {
HashSet<String> strSet=new HashSet<String>();
for(String str:words)
if(!strSet.contains(str))strSet.add(str);
//System.out.println(strSet);
List<String> res=new LinkedList<String>();
for(String str:words){
if(isok(str,strSet))res.add(str);
}
return res;
}

public static boolean isok(String str,HashSet<String> strSet){
if(str.length()==0)return false;
boolean[] dp=new boolean[str.length()+1];
dp[0]=true;
for(int i=1;i<str.length();i++){
for(int j=0;j<i;j++){
if(!dp[j])continue;
if(strSet.contains(str.substring(j,i))){
dp[i]=true;
break;
}
}
}
for(int i=1;i<str.length();i++)
if(dp[i]&&strSet.contains(str.substring(i,str.length()))){
dp[str.length()]=true;
break;
}
return dp[str.length()];
}