From 101e42244581831d533435915806887fdbcf0ddc Mon Sep 17 00:00:00 2001
From: ISHA AGGARWAL <244146795+IshaAggarwalDev@users.noreply.github.com>
Date: Mon, 23 Feb 2026 00:01:02 +0530
Subject: [PATCH 1/3] Create 0001_TwoSum_HashMap.java

---
 0001_TwoSum_HashMap.java | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
 create mode 100644 0001_TwoSum_HashMap.java

diff --git a/0001_TwoSum_HashMap.java b/0001_TwoSum_HashMap.java
new file mode 100644
index 0000000..691a685
--- /dev/null
+++ b/0001_TwoSum_HashMap.java
@@ -0,0 +1,17 @@
+class Solution {
+    public int[] twoSum(int[] nums, int target) {
+        HashMap<Integer, Integer> map = new HashMap<>();
+
+        for (int i = 0; i < nums.length; i++) {
+            int complement = target - nums[i];
+
+            if (map.containsKey(complement)) {
+                return new int[] { map.get(complement), i };
+            }
+
+            map.put(nums[i], i);
+        }
+
+        return new int[] {}; 
+    }
+}

From 56292d2b86137b675c3e4b463d5b4662e635e064 Mon Sep 17 00:00:00 2001
From: ISHA AGGARWAL <244146795+IshaAggarwalDev@users.noreply.github.com>
Date: Mon, 23 Feb 2026 00:01:51 +0530
Subject: [PATCH 2/3] Create 0128_Longest_Consecutive_Sequence.java

---
 0128_Longest_Consecutive_Sequence.java | 34 ++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 0128_Longest_Consecutive_Sequence.java

diff --git a/0128_Longest_Consecutive_Sequence.java b/0128_Longest_Consecutive_Sequence.java
new file mode 100644
index 0000000..65c0494
--- /dev/null
+++ b/0128_Longest_Consecutive_Sequence.java
@@ -0,0 +1,34 @@
+import java.util.HashSet;
+
+class Solution {
+    public int longestConsecutive(int[] nums) {
+        
+        HashSet<Integer> set = new HashSet<>();
+        
+        // Add all numbers to set
+        for (int num : nums) {
+            set.add(num);
+        }
+        
+        int longest = 0;
+        
+        for (int num : set) {
+            
+            // Check if it's the start of a sequence
+            if (!set.contains(num - 1)) {
+                
+                int currentNum = num;
+                int currentStreak = 1;
+                
+                while (set.contains(currentNum + 1)) {
+                    currentNum++;
+                    currentStreak++;
+                }
+                
+                longest = Math.max(longest, currentStreak);
+            }
+        }
+        
+        return longest;
+    }
+}

From 9749db9106c600eba4be749247171db6fa1329dd Mon Sep 17 00:00:00 2001
From: ISHA AGGARWAL <244146795+IshaAggarwalDev@users.noreply.github.com>
Date: Mon, 23 Feb 2026 00:07:07 +0530
Subject: [PATCH 3/3] Update README.md

---
 README.md | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/README.md b/README.md
index 9f0fa45..a0ad2c0 100644
--- a/README.md
+++ b/README.md
@@ -1,17 +1,19 @@
-# LeetCode Solutions
+# Hashing
 
-This repository contains my solutions to LeetCode problems as part of my Data Structures and Algorithms practice.
+## 1. Two Sum
+Problem Link: https://leetcode.com/problems/two-sum/
+Difficulty: Easy
+### Approach : HashMap (Optimized)
+Time Complexity: O(n)
+Space Complexity: O(n)
+### Concepts Used:
+Array Traversal,HashMap,Complement Technique,Single Pass Algorithm,Key-Value Mapping
 
-The goal of this repository is to improve problem-solving skills and prepare for technical interviews and placements.
-
-## Topics Covered
-- Arrays
-- Strings
-- Linked List
-- Stack
-- Queue
-- Recursion
-- Hashing
-- Binary-Search
-- Prefix-Sum
-- Math
+## 128. Longest Consecutive Sequence
+Problem Link: https://leetcode.com/problems/longest-consecutive-sequence/
+Difficulty: Medium
+### Approach: HashSet (Optimized)
+Time Complexity: O(n)
+Space Complexity: O(n)
+### Concepts Used:
+HashSet, Sequence Pattern, Array Traversal