How should I practice Longest Substring Without Repeating Characters?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Benchling onsite interview problems in FastPrep.

Is Longest Substring Without Repeating Characters associated with Benchling?

FastPrep tags this as a Benchling onsite interview coding practice problem when the problem catalog has that company and stage context.

Longest Substring Without Repeating Characters

Benchling● MediumFULLTIMEONSITE INTERVIEW

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Problem statement

Given a string s, return the length of its longest contiguous substring that contains no repeated characters.

Interview follow-up

The report also describes allowing k repeats, without defining what counts as a repeat. For this exercise, assume the discussion variant counts total excess occurrences: sum(max(0,count[c]-1)) <= k. Explain how to maintain that budget in a sliding window. This variant is discussion only; the judged function still requires no repeated character.

Function

lengthOfLongestSubstring(s: String) → int

Examples

Example 1

s = "abcabcbb"return = 3

"abc" is a longest substring without repeated characters, so the answer is 3.

Example 2

s = "bbbbb"return = 1

Every substring with distinct characters contains at most one b.

Constraints

1 <= s.length <= 10^5.
s contains English letters, digits, and common symbols.