Word Break--Leetcode

Question:

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".

Answer:

class Solution {

public:

    bool wordBreak(string s, unordered_set<string> &dict) {

    vector<bool> wordB(s.length() + 1);

    wordB[0] = true;

    for (int i = 1; i < s.length() + 1; i++) {

        for (int j = i - 1; j >= 0; j--) {

            if (wordB[j] && dict.find(s.substr(j, i - j)) != dict.end()) {

                wordB[i] = true;

                break;

            }

        }

    }  

    return wordB[s.length()];

    }

};