[LeetCode]Word Break

2015-01-24 05:33:21 · 作者: · 浏览: 3

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".


利用递归动态规划,而且递归的条件要有限制

public class Solution {
	boolean f[];
    public boolean wordBreak(String s, Set
  
    dict) {
    	f = new boolean[s.length()];
    	wordBreak(s,dict,0);
    	return f[s.length()-1];
    }
    
    private void wordBreak(String s, Set
   
     dict,int index){ if(index>=s.length()) return; for(int i=index;i
    
     

参考九章算法,提取出set里字符串的最长距离,可以进一步减小算法

public class Solution {
	boolean f[];
	int maxLen = Integer.MIN_VALUE;

    public boolean wordBreak(String s, Set
      
        dict) {
    	f = new boolean[s.length()];
    	maxLength(dict);
    	wordBreak(s,dict,0);
    	return f[s.length()-1];
    }
    
    private void wordBreak(String s, Set
       
         dict,int index){ if(index>=s.length()) return; for(int i=index;i
        
          dict){ Iterator
         
           it = dict.iterator(); while(it.hasNext()){ maxLen = Math.max(maxLen, it.next().length()); } } }