Bit Set Problem Statement

You are provided with a string, termed as DIGIT_PATTERN, which consists solely of digits. The objective is to identify the first digit that repeats in the sequence. If there's no repeating digit, the result should be -1.

Example:

Input:

123456325

Output:

3

Explanation:

In the given string 123456325, as we move from left to right, digit '3' is the first to repeat, making it our answer.

Constraints:

• 1 <= T <= 10
• 1 <= |DIGIT_PATTERN| <= 10^5
• 0 <= DIGIT_PATTERN[i] <= 9

Note:

You do not need to print anything; just return the answer for each test case.