Description
A string s is good if there are no two different characters with the same frequency. Return the minimum number of character deletions to make s good.
Examples
Input:
s = "aab"Output:
0Explanation:
Already good: a=2, b=1.
Input:
abcabcOutput:
3Explanation:
Initial frequencies: a=2, b=2, c=2. All characters have the same frequency (2), so the task requires make them unique. It is possible to keep one character at frequency 2, reduce another to frequency 1, and reduce the third to frequency 0. This requires deleting 1+2=3 characters total.
Input:
ceabaacbOutput:
2Explanation:
Initial frequencies: a=3, b=2, c=2, e=1. Characters b and c both have frequency 2, which violates the uniqueness requirement. It is possible to keep b at frequency 2 and reduce c to frequency 1, but frequency 1 is already taken by e. So reducing c to frequency 0 by deleting 2 characters.
Constraints
- •
1 ≤ s.length ≤ 10^5