Ezvor

3. Longest Substring Without Repeating Characters

MediumHash Table Preparing judge… LeetCode

Given a string s, find the length of the longest substring without duplicate characters.

 

Example 1:

Input: s = "abcabcbb"
Output: 3
Explanation: The answer is "abc", with the length of 3. Note that "bca" and "cab" are also correct answers.

Example 2:

Input: s = "bbbbb"
Output: 1
Explanation: The answer is "b", with the length of 1.

Example 3:

Input: s = "pwwkew"
Output: 3
Explanation: The answer is "wke", with the length of 3.
Notice that the answer must be a substring, "pwke" is a subsequence and not a substring.

 

Constraints:

  • 0 <= s.length <= 105
  • s consists of English letters, digits, symbols and spaces.
Hash TableStringSliding Window

Hints

Hint 1
There are less than 100 unique characters. We can check all substrings with length at most 100 for example. This is a good enough approximation.