[LeetCode] Word Break

Given a string s and a dictionary of words dict, determine if s can be segmented into a space-separated sequence of one or more dictionary words.

For example, given
s =

"leetcode"

,
dict =

["leet", "code"]

.

Return true because

"leetcode"

can be segmented as

"leet code"

.

这道题还是挺有难度的。重点是dynamic programming的应用。用boolean[]来判断true/false与否。记得除了contians()的条件外还要判断两个被分开的单词是否连在一起这样的问题。

代码如下。~

public class Solution {
public boolean wordBreak(String s, Set<String> wordDict) {
if(s==null&&s.length()==0){
return false;
}
int len=s.length();

boolean[] test=new boolean[len];
for(int i=0;i<len;i++){
for(int j=0;j<=i;j++){
String sub=s.substring(j,i+1);
if(wordDict.contains(sub)&&(j==0||test[j-1])){
test[i]=true;
break;
}
}
}
return test[len-1];
}
}