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".

写个一个递归算法，超时，网上查了下，大家都用DP实现，暂时先放一放，DP总觉得比较难。

class Solution {public:    bool wordBreak(string s, unordered_set<string> &dict) {    //i represent length of substr    for (int i = 1; i < s.size(); i++)    {    string word = s.substr(0, i);    if (dict.count(word) != 0)    {    if (wordBreak(s.substr(i+1), dict))    return true;    }    }        return false;                      }};