For this problem in Weekly Contest 207:-
1593. Split a String Into the Max Number of Unique Substrings

I think there were some wrong test cases on which our submission was being evaluated.

Input:
"addbsd"
Output:
4
Expected:
5

The length of the input given is 6, with 3 characters as same(3 'd' characters)
So in any case, I can keep 1 'd' as a separate split and 2 other 'd' characters, I need to combine with some other characters.
So for sure for this test case, the answer should be <=4

But the expected answer is given to be 5.
How is it possible?
Please check the issue as it seems unfair to me