Given a string S, we can transform every letter individually to be lowercase or uppercase to create another string. Return a list of all possible strings we could create.
列举出字符串中在字母有大小写两种情况下的所有可能组合。
Examples:
Input: S = "a1b2"
Output: ["a1b2", "a1B2", "A1b2", "A1B2"]
Input: S = "3z4"
Output: ["3z4", "3Z4"]
Input: S = "12345"
Output: ["12345"]
Note:
S
will be a string with length at most12
.
S
will consist only of letters or digits.
class Solution:
def letterCasePermutation(self, S):
"""
:type S: str
:rtype: List[str]
"""
cur_s = [S]
for i in range(len(S)):
next_s = []
for s in cur_s:
if s[i].isdigit():
next_s.append(s)
else:
next_s.append(s[0:i] + s[i].lower() + s[i+1:])
next_s.append(s[0:i] + s[i].upper() + s[i+1:])
cur_s = next_s
return cur_s