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Longest Substring without Repeating Characters

Explore how to use the sliding window technique to find the longest substring without repeating characters in a string. Understand the problem constraints, apply a step-by-step approach, and implement your solution in a coding environment to build efficient string manipulation skills.

Statement

Given a string, str, return the length of the longest substring without repeating characters.

Constraints:

  • 11 \leq str.length 105\leq 10^5
  • str consists of English letters, digits, and spaces.

Examples

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Understand the problem

Let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps us to check if you’re solving the correct problem:

Longest Substring Without Repeating Characters

1.

What should be the output if the following string is given as an input?

s = “conceptoftheday”

A.

8

B.

6

C.

5

D.

13


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Figure it out!

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Sequence - Vertical
Drag and drop the cards to rearrange them in the correct sequence.

1
2
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5
6

Try it yourself

Implement your solution in the following coding playground:

JavaScript
usercode > main.js
export function findLongestSubstring(str) {
// Replace this placeholder return statement with your code
return -1;
}
Longest Substring without Repeating Characters