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 Nykaa phone screen problems in FastPrep.

Is Longest Substring Without Repeating Characters associated with Nykaa?

FastPrep tags this as a Nykaa phone screen coding practice problem when the problem catalog has that company and stage context.

Longest Substring Without Repeating Characters

Nykaa● MediumFULLTIMEPHONE SCREEN

Problem statement

Given a string s, return the length of the longest substring of s in which every character is different.

A substring is a run of consecutive characters. Characters are compared exactly: A and a are different, and spaces, digits, and symbols are characters too.

If s is empty, return 0.

Function

lengthOfLongestSubstring(s: String) → int

Examples

Example 1

s = "abcbdeb"return = 4

The substring "cbde" has 4 different characters. Every substring of length 5 contains b twice, so the answer is 4.

Example 2

s = "aaaa"return = 1

Any substring longer than one character repeats a, so the answer is 1.

Example 3

s = "Hi, hi!"return = 5

H and h are different characters, and the comma and the space count as characters too. "Hi, h" has 5 different characters. Both substrings of length 6 contain i twice, so the answer is 5.

Constraints

0 <= s.length <= 5 * 10^4
s contains only printable ASCII characters (codes 32 to 126): English letters, digits, spaces, and symbols.