Minimum Deletions to Make String Balanced
You are given a string s consisting only of characters 'a' and 'b'.
You can delete any number of characters in s to make s balanced. s is balanced if there is no pair of indices (i, j) such that i < j, s[i] = 'b', and s[j] = 'a'.
Return the minimum number of deletions needed to make s balanced.
Example 1
Input
s = "aababbab"Output
2You can delete the characters at 0-indexed positions 2 and 6 to get "aaabbb", or delete the characters at positions 3 and 6 to get "aabbbb".
Example 2
Input
s = "bbaaaaabb"Output
2The only solution is to delete the first two characters.
Constraints
- 1 <= s.length <= 10^5
- s[i] is 'a' or 'b'.