Today I have done leetcode's January LeetCoding Challenge with cpp.

January LeetCoding Challenge 1

Description

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.

Solution

auto speedup = [](){
  cin.tie(nullptr);
  cout.tie(nullptr);
  ios::sync_with_stdio(false);
  return 0;
}();
class Solution {
public:
  int maxScore(string s) {
    int score = 0;
    for(auto c : s) {
      score += c - '0';
    }
    int maxScore = INT_MIN;
    for(int i = 0; i < s.length() - 1; ++i) {
      if(s[i] == '0') {
        score += 1;
      } else {
        score -= 1;
      }
      maxScore = max(score, maxScore);
    }
    return maxScore;
  }
};

// Accepted
// 104/104 cases passed (0 ms)
// Your runtime beats 100 % of cpp submissions
// Your memory usage beats 38.26 % of cpp submissions (8.8 MB)