https://leetcode.com/problems/count-sorted-vowel-strings/submissions/

class Solution {
public:
    int countVowelStrings(int n) {

        if(n==1) return 5;

        int sum = 0;
        int a[5] = {1,1,1,1,1};


        for(int i=1;i<n;i++){

            a[0] = a[0]+a[1]+a[2]+a[3]+a[4];
            a[1] = a[1]+a[2]+a[3]+a[4];
            a[2] = a[2]+a[3]+a[4];
            a[3] = a[3]+a[4];
            a[4] = a[4];

            sum = a[0]+a[1]+a[2]+a[3]+a[4];
        }

        return sum;
    }
};