Maximum Score After Splitting a String

# 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
 ```

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

/**
 * @param {string} s
 * @return {number}
 */
 var maxScore = function(s) {
    let max = -1, oneCnt = s.split('1').length - 1, zeroCnt = 0;
    for (let i = 0; i < s.length - 1; i++) {  
        s[i] === '0' ? zeroCnt++ : oneCnt--;
        max = Math.max(zeroCnt + oneCnt, max);
    }    
    return max;
};