Question

1422. Maximum Score After Splitting a String

中文文档

Description

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

Solution 1

class Solution:
  def maxScore(self, s: str) -> int:
    return max(s[:i].count('0') + s[i:].count('1') for i in range(1, len(s)))

class Solution {
  public int maxScore(String s) {
    int ans = 0;
    for (int i = 1; i < s.length(); ++i) {
      int t = 0;
      for (int j = 0; j < i; ++j) {
        if (s.charAt(j) == '0') {
          ++t;
        }
      }
      for (int j = i; j < s.length(); ++j) {
        if (s.charAt(j) == '1') {
          ++t;
        }
      }
      ans = Math.max(ans, t);
    }
    return ans;
  }
}

class Solution {
public:
  int maxScore(string s) {
    int ans = 0;
    for (int i = 1, n = s.size(); i < n; ++i) {
      int t = 0;
      for (int j = 0; j < i; ++j) {
        t += s[j] == '0';
      }
      for (int j = i; j < n; ++j) {
        t += s[j] == '1';
      }
      ans = max(ans, t);
    }
    return ans;
  }
};

func maxScore(s string) int {
  ans := 0
  for i, n := 1, len(s); i < n; i++ {
    t := 0
    for j := 0; j < i; j++ {
      if s[j] == '0' {
        t++
      }
    }
    for j := i; j < n; j++ {
      if s[j] == '1' {
        t++
      }
    }
    ans = max(ans, t)
  }
  return ans
}

function maxScore(s: string): number {
  const n = s.length;
  let res = 0;
  let score = 0;
  if (s[0] === '0') {
    score++;
  }
  for (let i = 1; i < n; i++) {
    if (s[i] === '1') {
      score++;
    }
  }
  res = Math.max(res, score);
  for (let i = 1; i < n - 1; i++) {
    if (s[i] === '0') {
      score++;
    } else if (s[i] === '1') {
      score--;
    }
    res = Math.max(res, score);
  }
  return res;
}

impl Solution {
  pub fn max_score(s: String) -> i32 {
    let n = s.len();
    let mut res = 0;
    let mut score = 0;
    let bs = s.as_bytes();
    if bs[0] == b'0' {
      score += 1;
    }
    for i in 1..n {
      if bs[i] == b'1' {
        score += 1;
      }
    }
    res = res.max(score);
    for i in 1..n - 1 {
      if bs[i] == b'0' {
        score += 1;
      } else if bs[i] == b'1' {
        score -= 1;
      }
      res = res.max(score);
    }
    res
  }
}

Solution 2

class Solution:
  def maxScore(self, s: str) -> int:
    ans = t = (s[0] == '0') + s[1:].count('1')
    for i in range(1, len(s) - 1):
      t += 1 if s[i] == '0' else -1
      ans = max(ans, t)
    return ans

class Solution {
  public int maxScore(String s) {
    int t = 0;
    if (s.charAt(0) == '0') {
      t++;
    }
    for (int i = 1; i < s.length(); ++i) {
      if (s.charAt(i) == '1') {
        t++;
      }
    }
    int ans = t;
    for (int i = 1; i < s.length() - 1; ++i) {
      t += s.charAt(i) == '0' ? 1 : -1;
      ans = Math.max(ans, t);
    }
    return ans;
  }
}

class Solution {
public:
  int maxScore(string s) {
    int t = 0;
    if (s[0] == '0') ++t;
    for (int i = 1; i < s.size(); ++i) t += s[i] == '1';
    int ans = t;
    for (int i = 1; i < s.size() - 1; ++i) {
      t += s[i] == '0' ? 1 : -1;
      ans = max(ans, t);
    }
    return ans;
  }
};

func maxScore(s string) int {
  t := 0
  if s[0] == '0' {
    t++
  }
  n := len(s)
  for i := 1; i < n; i++ {
    if s[i] == '1' {
      t++
    }
  }
  ans := t
  for i := 1; i < n-1; i++ {
    if s[i] == '0' {
      t++
    } else {
      t--
    }
    ans = max(ans, t)
  }
  return ans
}