LeetCode1422. Maximum Score After Splitting a String

一、题目

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.

二、题解

class Solution {
public:
    int maxScore(string s) {
        int n = s.size();
        int maxNum = 0;
        for(int i = 1;i < n;i++){
            int leftZero = 0,rightOne = 0;
            for(int j = 0;j < i;j++) if(s[j] == '0') leftZero++;
            for(int k = i;k < n;k++) if(s[k] == '1') rightOne++;
            maxNum = max(maxNum,leftZero+rightOne);
        }
        return maxNum;
    }
};