super30admin · sneha-tambade · Jan 14, 2026
diff --git a/Problem1.cpp b/Problem1.cpp
diff --git a/Problem1.java b/Problem1.java
diff --git a/Problem2.cpp b/Problem2.cpp
diff --git a/Problem2.java b/Problem2.java
diff --git a/TwoSum.cs b/TwoSum.cs
@@ -0,0 +1,28 @@
+//Time Complexity - O(n)
+//Space Complexity - O(n)
+
+// Iterate over an array calculate sum= element - target, check if dictionary contains sum , if not then add element and its index in dictionary.
+
+// If the sum is in the dictionary then return index stored at the sum and current index.
+
+public class Solution
+{
+    public int[] TwoSum(int[] nums, int target)
+    {
+        //Dictionaries O(n)
+        var pairs = new Dictionary<int, int>();
+        int sum = 0;
+        for (int i = 0; i < nums.Length; i++)
+        {
+            sum = target - nums[i];
+            if (pairs.ContainsKey(sum))
+                return new int[] { pairs[sum], i };
+            else
+                pairs.TryAdd(nums[i], i);
+        }
+        return default;
+    }
+}
+
+
+