LeetCode | Longest Substring Without Repeating Characters | Java Solution

 Longest Substring Without Repeating Characters

Problem link - Longest Substring Without Repeating Characters

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

Example 1:

Input: s = "abcabcbb"
Output: 3
Explanation: The answer is "abc", with the length of 3.

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.

Solution

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

class Solution { public int lengthOfLongestSubstring(String s) { int right = 0; int left = 0; Set<Character> set = new HashSet<>(); int maxLength = 0; while (left < s.length() && right < s.length()) { if (!set.contains(s.charAt(right))) { set.add(s.charAt(right)); maxLength = Math.max(maxLength, set.size()); right++; } else { set.remove(s.charAt(left)); left++; } } return maxLength; } }