1422. Maximum Score After Splitting a String

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.

这题可以先求出1的个数，然后再遍历字符串，遇到0增加0的次数，反之减少1的次数，求出它们的和，并找出它们的和中最大的值即可。

class MaximumScoreAfterSplittingAString : public Solution {
public:
    void Exec() {

    }
    int maxScore(string s) {
        int maxValue = 0;
        int countOfOne = 0;
        for (auto c : s) {
            if (c == '1') {
                countOfOne++;
            }
        }

        int zeroScore = 0;
        int oneScore = countOfOne;
        for (int i = 0; i < s.size() - 1; i++) {
            if (s[i] == '0') {
                zeroScore++;
            } else {
                oneScore--;
            }
            if (zeroScore + oneScore > maxValue) {
                maxValue = zeroScore + oneScore;
            }
        }
        return maxValue;
    }
};