class Solution { public int countVowelStrings(int n) { int[][] dp = new int[n + 1][5]; for (int i = 0; i < 5; i++) { dp[0] = 1; } for (int i = 0; i < 5; i++) { for (int j = 1; j < n; j++) { int cur = 0; for (int k = 0; k <= i; k++) { cur += dp[j - 1][k]; } dp[j] = cur; } } int ans = 0; for (int i = 0; i < 5; i++) { ans += dp[n - 1]; } return ans; }}
