README.md

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.

Solutions (Rust)

1. Solution

impl Solution {
    pub fn max_score(s: String) -> i32 {
        let s = s.into_bytes();
        let mut score_l = (b'1' - s[0]) as i32;
        let mut score_r = s[1..].iter().filter(|&&ch| ch == b'1').count() as i32;
        let mut ret = score_l + score_r;

        for i in 1..(s.len() - 1) {
            match s[i] {
                b'0' => score_l += 1,
                _ => score_r -= 1,
            }
            ret = ret.max(score_l + score_r);
        }

        ret
    }
}