[Medium] Title: 3. Longest Substring Without Repeating Characters - LeetCode

Author: JinHyung-dev

LeetCode/Medium/3. Longest Substring Without Repeating Characters/Longest Substring Without Repeating Characters.java

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+class Solution {
+    public int lengthOfLongestSubstring(String s) {
+        Set<Character> seen = new HashSet<>();
+        int length = 0; int start = 0;
+
+        for(int end = 0; end < s.length(); end++){
+            // 중복 문자 확인
+            while(seen.contains(s.charAt(end)) {
+                seen.remove(s.charAt(start));
+                start++;
+            }
+
+            seen.add(s.charAt(end));  // 새로운 문자 추가
+            length = Math.max(length, end - start + 1);  // 길이 수정
+        }
+
+        return length;
+    }
+}

LeetCode/Medium/3. Longest Substring Without Repeating Characters/README.md

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+# [Midium] 3. Longest Substring Without Repeating Characters
+
+[문제 링크](https://leetcode.com/problems/longest-substring-without-repeating-characters/)
+
+### 문제 설명
+
+Given a string s, find the length of the longest
+substring without repeating characters.
+
+### 입출력
+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.
+
+### 제약조건
+- 0 <= s.length <= 5 * 104
+- s consists of English letters, digits, symbols and spaces.