Word Break.cpp

class Solution {
public:
    bool wordBreak(string s, vector<string>& wordDict) {
        int len = s.size();
        unordered_set<string> dict(wordDict.begin(), wordDict.end());
        vector<bool> dp(len + 1, false);
        dp[0] = true;
        for(int i = 0; i < len; ++i)
        {
            for(int j = 0; j <= i; ++j)
            {
                string str = s.substr(j, i - j + 1);
                if(dict.find(str) != dict.end() && dp[j])
                {
                    dp[i + 1] = true;
                    break;
                }
            }
        }
        return dp[len];
    }
};