1422. Maximum Score After Splitting a String

Problem Link

Description

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Given a string s of zeros and ones, return the maximum score after splitting the string into two non-empty substrings (i.e. left substring and right substring).

The score after splitting a string is the number of zeros in the left substring plus the number of ones in the right substring.

 

Example 1:

Input: s = "011101"
Output: 5 
Explanation: 
All possible ways of splitting s into two non-empty substrings are:
left = "0" and right = "11101", score = 1 + 4 = 5 
left = "01" and right = "1101", score = 1 + 3 = 4 
left = "011" and right = "101", score = 1 + 2 = 3 
left = "0111" and right = "01", score = 1 + 1 = 2 
left = "01110" and right = "1", score = 2 + 1 = 3

Example 2:

Input: s = "00111"
Output: 5
Explanation: When left = "00" and right = "111", we get the maximum score = 2 + 3 = 5

Example 3:

Input: s = "1111"
Output: 3

 

Constraints:

• 2 <= s.length <= 500
• The string s consists of characters '0' and '1' only.

Solution

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Python3

class Solution:
    def maxScore(self, s: str) -> int:
        N = len(s)
        rightOnes = s.count("1")
        leftZeroes = 0
        res = 0
 
        for x in s[:-1]:
            if x == "0":
                leftZeroes += 1
            else:
                rightOnes -= 1
 
            res = max(res, leftZeroes + rightOnes) 
 
        return res