[leetcode]139. Word Break(Java)

https://leetcode.com/problems/word-break/#/description

Given a non-empty string s and a dictionary wordDict containing a list of non-empty words, determine if s can be segmented
into a space-separated sequence of one or more dictionary words. You may assume the dictionary does not contain duplicate words.

For example, given
s = 

"leetcode"

,
dict = 

["leet", "code"]

.

Return true because 

"leetcode"

 can be segmented as 

"leet
code"

.

UPDATE (2017/1/4):

The wordDict parameter had been changed to a list of strings (instead of a set of strings). Please reload the code definition to get the latest changes.

package go.jacob.day715;

import java.util.List;

/**
* 139. Word Break
*
* @author Administrator 题意：把wordDict中的元素进行组合，可以重复使用，是否可以拼成s
*/
public class Demo3 {
public boolean wordBreak(String s, List<String> wordDict) {
boolean[] res = new boolean[s.length() + 1];
res[0] = true;

//i循环的目的是，确定能不能拼成以i为下标结尾的字符串
for (int i = 1; i <= s.length(); i++) {
for (int j = 0; j < i; j++) {
if(res[j]&&wordDict.contains(s.substring(j, i))){
res[i]=true;
//只要找到一个 能拼成以i为下标结尾的字符串，就可以跳出循环
break;
}
}
}

return res[s.length()];
}
}