class Solution {
public:
    int minExtraChar(string s, vector<string>& d) {
        int n = s.size();
        vector<int> f(n + 1);
        for (int i = 0; i < n; i++) {
            string t; 
            for (int k = i; k < n; k++) {
                t += s[k];
                for (int r = 0; r < d.size(); r++) {
                    if (t == d[r]) {
                        f[i]++, f[k + 1]--;
                    }
                }
            }
        }
        for (int i = 0; i < n; i++) {
            f[i + 1] += f[i];
        }
        int ans = 0;
        for (int i = 0; i < n; i++) {
            if (f[i] == 0) ans += 1;
        }
        return ans;
    }
};

s = "kevlplxozaizdhxoimmraiakbak",
d = ["yv","bmab","hv","bnsll","mra","jjqf","g","aiyzi","ip","pfctr","flr","ybbcl","biu","ke","lpl","iak","pirua","ilhqd","zdhx","fux","xaw","pdfvt","xf","t","wq","r","cgmud","aokas","xv","jf","cyys","wcaz","rvegf","ysg","xo","uwb","lw","okgk","vbmi","v","mvo","fxyx","ad","e"],
Expected Answer: 9, 
My output: 8