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".

bool wordBreak(string s, unordered_set<string> &dict) {
        vector<bool> f(s.size()+1,false);
        f[0] =true;
        for(int i=1;i<=s.size();i++)
            {
                for(int j=i-1;j>=0;j--)
                    if(f[j] &&dict.find(s.substr(j,i-j))!=dict.end())
                    {
                        f[i] =true;
                        break;
                    }
            }
            return f[s.size()];
    }