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 and s[i] = 'b' and s[j]= 'a'.
Return the minimum number of deletions needed to make s balanced.
Examples
Example 1
Input: s = "aababbab"
Output: 2
Explanation: You can either:
Delete the characters at 0-indexed positions 2 and 6 ("aababbab" -> "aaabbb"), or
Delete the characters at 0-indexed positions 3 and 6 ("aababbab" -> "aabbbb").
Example 2
Input: s = "bbaaaaabb"
Output: 2
Explanation: The only solution is to delete the first two characters.
Constraints
1 <= s.length <= 105
s[i] is 'a' or 'b'.
1653. Minimum Deletions to Make String Balanced
Medium
30 Points
String
Dynamic Programming
Stack
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 and s[i] = 'b' and s[j]= 'a'.
Return the minimum number of deletions needed to make s balanced.
Examples
Example 1
Input: s = "aababbab"
Output: 2
Explanation: You can either:
Delete the characters at 0-indexed positions 2 and 6 ("aababbab" -> "aaabbb"), or
Delete the characters at 0-indexed positions 3 and 6 ("aababbab" -> "aabbbb").
Example 2
Input: s = "bbaaaaabb"
Output: 2
Explanation: The only solution is to delete the first two characters.
Constraints
1 <= s.length <= 105
s[i] is 'a' or 'b'.
Minimum Deletions to Make String Balanced - Practice Coding | SlaveCode