class Solution {
    public List<String> getValidT9Words(String num, String[] words) {
        String s = "22233344455566677778889999";
        int[] d = new int[26];
        for (int i = 0; i < 26; ++i) {
            d[i] = s.charAt(i);
        }
        List<String> ans = new ArrayList<>();
        int n = num.length();
        for (String w : words) {
            boolean ok = true;
            for (int i = 0; i < n; ++i) {
                if (d[w.charAt(i) - 'a'] != num.charAt(i)) {
                    ok = false;
                    break;
                }
            }
            if (ok) {
                ans.add(w);
            }
        }
        return ans;
    }
}