From ecbcea486bec4ef5331641868a4a6b1f94084a39 Mon Sep 17 00:00:00 2001
From: Ly Na Nguyen <39471975+Lynanguyen0515@users.noreply.github.com>
Date: Fri, 12 May 2023 23:44:02 -0400
Subject: [PATCH] Create 0003_longest_substring_without_repeating_character

---
 ...gest_substring_without_repeating_character | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 python_solutions/0003_longest_substring_without_repeating_character

diff --git a/python_solutions/0003_longest_substring_without_repeating_character b/python_solutions/0003_longest_substring_without_repeating_character
new file mode 100644
index 0000000..b644739
--- /dev/null
+++ b/python_solutions/0003_longest_substring_without_repeating_character
@@ -0,0 +1,24 @@
+//using sliding window
+
+import java.util.HashSet;
+import java.util.Set;
+
+class Solution {
+    public int lengthOfLongestSubstring(String s) {
+        // HashSet to store the current window of unique characters
+        Set<Character> set = new HashSet<>();
+        int n = s.length();
+        int ans = 0, i = 0, j = 0;
+        while (i < n && j < n) {
+            // try to extend the range [i, j]
+            if (!set.contains(s.charAt(j))){
+                set.add(s.charAt(j++));
+                ans = Math.max(ans, j - i);
+            }
+            else {
+                set.remove(s.charAt(i++));
+            }
+        }
+        return ans;
+    }
+}