leetcode1422. Maximum Score After Splitting a String

Posted 2020-12-23 seyjs

题目如下：

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.

解题思路：很简单的题目。

代码如下：

class Solution(object):
    def maxScore(self, s):
        """
        :type s: str
        :rtype: int
        """
        count_1 = s.count(‘1‘)
        res = 0
        sub_count_1 = 0
        sub_count_0 = 0
        for i in s[:-1]:
            if i == ‘0‘:
                sub_count_0 += 1
            else:
                sub_count_1 += 1

            res = max(res,sub_count_0 + (count_1 - sub_count_1))

        return res