Max Unique Substring Length in a Session

Origin: Max Unique Substring Length in a Session

Given a string of lowercase letters with sessions separated by ” characters, find the maximum length of a substring with all distinct letters within any single session.

Example

Input

sessionString = abcabcbb

Output

3

Explanation

• There is only one session: “abcabcbb”.
• Scanning with a sliding window for distinct letters, the longest substrings without repeats are “abc”, “bca” and so on, each of length 3.
• Therefore, the result is 3.

Input Format

• A single line containing the string sessionString.

Constraints

- 0 <= S.length <= 100000
- For all i in [0, S.length]: S[i] is either '*' or a lowercase letter 'a' to 'z'
- Each session is defined as a maximal contiguous substring of S without '*' characters
- Number of sessions (segments between '*') is at most S.length + 1

Output Format

• A single integer denoting the maximum length among all substrings. If sessionString is empty or contains only ’*’, output 0.

Sample Input 0

*

Sample Output 0

0

Sample Input 1

aa

Sample Output 1

1

Resolution

function maxDistinctSubstringLengthInSessions(sessionString: string): number {
  // Write your code here
  let left = 0;
  let maxLength = 0;
  const charSet = new Set();
  for (let right = 0; right < sessionString.length; right++) {
    const char = sessionString[right];
    if (char === '*') {
      charSet.clear();
      left = right + 1;
    }
    else {
      while (charSet.has(char)) {
        charSet.delete(sessionString[left]);
        left++;
      }
      charSet.add(char);
      maxLength = Math.max(maxLength, right - left + 1);
    }
  }
  return maxLength;
}