[leetcode]Word Break

问题描述：

Given a string s and a dictionary of wordsdict, 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".

基本思想：

动态规划思想： 保存每个子串S（i，j）是否可分的信息。从小到大构建可分性表格。

代码：

    public boolean wordBreak(String s, Set<String> dict) {  //java    if(s.isEmpty())        return true;    if(dict.contains(s))        return true;        int len = s.length();    int [][] record = new int[len+1][len+1];    for(int i=0; i<=len; i++)        record[i][i]=1;        for(int step=1; step<=len; step++)    {        for(int j=step; j<=len; j++)        {            int i=j-step;            if(dict.contains(s.substring(i,j)))             {                 record[i][j]=1;                 continue;             }                          for(int k=i+1; k<j; k++)             {                 if(record[i][k]==1 && record[k][j]==1)                 {                    record[i][j] = 1;                       break;                 }             }        }    }        if(record[0][len] == 1) return true;    else return false;    }