AlgoDaily - Longest Substring With No Duplicate Characters

Longest Substring With No Duplicate Characters (Medium)

Good afternoon! Here's our prompt for today.

You may see this problem at Intercom, Pivotal, Nvidia, Canva, Segment, Carta, Figma, Weave, Amplitude, 3m, Veeva Systems, and Digitate.

Given a string of characters, can you find the longest substring of the string that has no repeating characters?

An example is shown below:

JAVASCRIPT

1lengthOfLongestSubstring("abracadabar");
2// 4 because it is 'brac'

Constraints

Length of the string <= 100000
The string will only contain lowercase letters
Expected time complexity : O(n)
Expected space complexity : O(1)

In this challenge, we'll discuss a simple but efficient method for finding the longest substring with no repeating characters.

xxxxxxxxxx
​
 
var assert = require('assert');
​
var lengthOfLongestSubstring = function (s) {
  // fill this in
  return maximumLen;
};
​
try {
  assert.equal(lengthOfLongestSubstring('algodaily'), 7);
​
  console.log(
    'PASSED: ' +
      "`lengthOfLongestSubstring('algodaily')` should be equal to `7`"
  );
} catch (err) {
  console.log(err);
}
​
try {
  assert.equal(lengthOfLongestSubstring('thisisatest'), 5);
​
  console.log(
    'PASSED: ' +
      "`lengthOfLongestSubstring('thisisatest')` should be equal to `5`"
  );
} catch (err) {
  console.log(err);

OUTPUT

Results will appear here.