You are given a string s of length n containing only four kinds of characters: 'Q', 'W', 'E', and 'R'.
A string is said to be balanced if each of its characters appears n / 4 times where n is the length of the string.
Return the minimum length of the substring that can be replaced with any other string of the same length to make s balanced. If s is already balanced, return 0.
Examples
Example 1
Input: s = "QWER"
Output: 0
Explanation: s is already balanced.
Example 2
Input: s = "QQWE"
Output: 1
Explanation: We need to replace a 'Q' to 'R', so that "RQWE" (or "QRWE") is balanced.
Example 3
Input: s = "QQQW"
Output: 2
Explanation: We can replace the first "QQ" to "ER".
Constraints
n == s.length
4 <= n <= 105
n is a multiple of 4.
s contains only 'Q', 'W', 'E', and 'R'.
1234. Replace the Substring for Balanced String
Medium
30 Points
String
Sliding Window
You are given a string s of length n containing only four kinds of characters: 'Q', 'W', 'E', and 'R'.
A string is said to be balanced if each of its characters appears n / 4 times where n is the length of the string.
Return the minimum length of the substring that can be replaced with any other string of the same length to make s balanced. If s is already balanced, return 0.
Examples
Example 1
Input: s = "QWER"
Output: 0
Explanation: s is already balanced.
Example 2
Input: s = "QQWE"
Output: 1
Explanation: We need to replace a 'Q' to 'R', so that "RQWE" (or "QRWE") is balanced.
Example 3
Input: s = "QQQW"
Output: 2
Explanation: We can replace the first "QQ" to "ER".
Constraints
n == s.length
4 <= n <= 105
n is a multiple of 4.
s contains only 'Q', 'W', 'E', and 'R'.
Replace the Substring for Balanced String - Practice Coding | SlaveCode