1220-count-vowels-permutation.py

classSolution: 
Memo= {} 
defcountVowelPermutation(self, n, c='') ->int: 
if (c, n) inself.Memo: 
returnself.Memo[(c, n)]
ifn==1:
ifc=='a':
return1
ifc=='e':
return2
ifc=='i':
return4
ifc=='o':
return2
ifc=='u':
return1
ifc=='': 
return5
else:
ifc=='a':
self.Memo[('a', n)] =self.countVowelPermutation(n-1, 'e') 
returnself.Memo[('a', n)]
ifc=='e':
self.Memo[('e', n)] =self.countVowelPermutation(n-1, 'a') +self.countVowelPermutation(n-1, 'i') 
returnself.Memo[('e', n)]
ifc=='i':
self.Memo[('i', n)] =self.countVowelPermutation(n-1, 'a') +self.countVowelPermutation(n-1, 'e') +self.countVowelPermutation(n-1, 'o') +self.countVowelPermutation(n-1, 'u') 
returnself.Memo[('i', n)]
ifc=='o':
self.Memo[('o', n)] =self.countVowelPermutation(n-1, 'i') +self.countVowelPermutation(n-1, 'u') 
returnself.Memo[('o', n)]
ifc=='u':
self.Memo[('u', n)] =self.countVowelPermutation(n-1, 'a') 
returnself.Memo[('u', n)]
ifc=='':
Tot=0
foriin ['a', 'e', 'i', 'o', 'u']:
Tot=Tot+self.countVowelPermutation(n-1, i); 
returnTot%1000000007