Identify the Added Letter
Company: Amazon
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: easy
Interview Round: Other
# Identify the Added Letter
String `t` was made by shuffling the letters of string `s` and adding one additional lowercase letter at some position. Return that added letter.
### Function
`char findTheDifference(string s, string t)`
### Example 1
```text
Input: s = "aba", t = "baaa"
Output: "a"
```
`t` contains one more `a` than `s` does.
### Example 2
```text
Input: s = "", t = "q"
Output: "q"
```
### Constraints
- `0 <= s.length <= 1000`.
- `t.length == s.length+1`.
- Both strings contain only lowercase English letters.
- `t` satisfies the stated shuffle-and-add construction.
### Clarifications
The added letter may already occur in `s`. Shuffling can change every position, so the first positional mismatch need not identify the added letter. Return a single character, not its index.
### What a Strong Answer Covers
- Rearrangement and repeated letters.
- An empty original string.
- Why the answer is the uniquely added occurrence's letter.
- Correctness and resource bounds.
Overview: Practice identifying one added lowercase letter after a string is shuffled. Handle repeated letters, an empty original string, and a character output.
