Letter Case Permutation
Given a string s, you can transform every letter individually to be lowercase or uppercase to create another string.
Return a list of all possible strings we could create. Return the output in any order.
Example 1
Input
s = "a1b2"Output
["a1b2","a1B2","A1b2","A1B2"]Each letter in
a1b2 can independently be lowercase or uppercase, while digits remain unchanged.Example 2
Input
s = "3z4"Output
["3z4","3Z4"]Only
z is a letter, so it can be either lowercase or uppercase while the digits remain unchanged.Constraints
- 1 <= s.length <= 12
- s consists of lowercase English letters, uppercase English letters, and digits.