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class Solution {
public:
    bool wordBreak(string s, vector<string>& wordDict) {
        set<string> word_set(wordDict.begin(), wordDict.end());
        vector<bool> dp(s.length() + 1);
        dp[0] = true;

        for(int i = 1; i <= s.length(); i++) {
            for(int j = 0; j < i; j++) {
                if(dp[j] && word_set.find(s.substr(j, i - j)) != word_set.end()) {
                    dp[i] = true;
                    break;
                }
            }
        }
        return dp[s.length()];
    }
};