# LeetCode-Alg-784-Letter Case Permutation

## LeetCode-Alg-784-Letter Case Permutation

Posted by Jae on May 29, 2019

### 1、题目

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.

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 between 1 and 12.
S will consist only of letters or digits.