# [Solution] Distinct Binary Strings solution codechef

Distinct Binary Strings solution codechef – You are given a binary string SS of length NN.

You have to perform the following operation exactly once:

• Select an index ii (1iN)(1≤i≤N) and delete SiSi from SS. The remaining parts of SS are concatenated in the same order.

How many distinct binary strings of length N1N−1 can you get after applying this operation?

# Distinct Binary Strings solution codechef

• The first line of input contains a single integer TT – the number of test cases. The description of TT test cases follow.
• The first line of each test case contains NN – the length of the binary string SS.
• The second line contains the binary string SS.

### Output Format

For each test case, output the number of distinct binary strings that you can get after applying the operation exactly once.

### Constraints

• 1T1051≤T≤105
• 2N1052≤N≤105
• Sum of NN does not exceed 21052⋅105 over all testcases.

## Distinct Binary Strings solution codechef

3
3
100
4
1111
5
10110


### Sample Output 1

2
1
4


### Distinct Binary Strings solution codechef

Test Case 1: We have S=100S=100. Now, we can get 0000 (on deleting S1S1), 1010 (on deleting S2S2) and 1010 (on deleting S3S3). Therefore, we can get 22 distinct strings.

Test Case 2: We have S=1111S=1111. Now, we will always get 111111 irrespective of the index ii on which we apply the operation. Therefore, we can get 11 distinct string