1220. Count Vowels Permutation.cpp

class Solution {
    vector<vector<int>> relation={{1,2,4},{0,2},{1,3},{2},{2,3}};
public:
    int countVowelPermutation(int n) {
        int MOD = 1e9+7;
        vector<long long> vowels(5,1),vowels_copy;      
        long long ans = 0;
        while(--n){
            vowels_copy = vowels;
            for(int i = 0; i < 5; i++){
                vowels[i] = 0;
                for(int &r:relation[i]){
                    vowels[i] += vowels_copy[r];
                    vowels[i] %= MOD; 
                } 
            }
        }
        
        for(long long &i:vowels){
            ans += i;
            ans %= MOD;
        }
        return ans;
    }
};