[LeetCode][Python3] 784. Letter Case Permutation

Problem :

https://leetcode.com/problems/letter-case-permutation/

My Solution :

class Solution:

def letterCasePermutation(self, S):

def dfs(path):

if len(path) == len(S):

ans.append(path)

return

c = S[len(path)]

if c.isupper():

dfs(path + c.lower())

dfs(path + c)

S = S.upper()

ans = []

dfs('')

return ans

My Solution 2 :

class Solution:

def letterCasePermutation(self, S):

S = S.upper()

ans = ['']

for c in S:

tmp = []

for prefix in ans:

if c.isupper():

tmp.append(prefix + c.lower())

tmp.append(prefix + c)

ans = tmp

return ans