leetcode139 Word Break

思路：
dp。
实现：
 1 class Solution 
 2 {
 3 public:
 4     bool judge(vector<string>& wordDict, string s)
 5     {
 6         return find(wordDict.begin(), wordDict.end(), s) != wordDict.end();
 7     }
 8     bool wordBreak(string s, vector<string>& wordDict) 
 9     {
10         vector<bool> dp(s.length() + 1, 0);
11         dp[0] = true;
12         for (int i = 1; i <= (int)s.length(); i++)
13         {
14             for (int j = 0; j < i; j++)
15             {
16                 if (dp[j] && judge(wordDict, s.substr(j, i - j)))
17                 {
18                     dp[i] = true;
19                 }
20             }
21         }
22         return dp[s.length()];
23     }
24 };