- Letter Case Permutation Medium
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. You can return the output in any order.
Example 1:
Input: S = "a1b2" Output: ["a1b2","a1B2","A1b2","A1B2"]
Example 2:
Input: S = "3z4" Output: ["3z4","3Z4"]
Example 3:
Input: S = "12345" Output: ["12345"]
Example 4:
Input: S = "0" Output: ["0"]
Constraints:
S will be a string with length between 1 and 12.
S will consist only of letters or digits.