From 806562b21c42aada02003ecafdc69fb0c12c2fb8 Mon Sep 17 00:00:00 2001
From: sneha-tambade <sneha.tambade06@gmail.com>
Date: Sat, 10 Jan 2026 23:27:45 -0800
Subject: [PATCH] TwoPointers-2 Implemented

---
 MergeSortedArray.cs                | 33 ++++++++++++++++++++++
 RemoveDuplicatesFromSortedArray.cs | 45 ++++++++++++++++++++++++++++++
 SearchIn2DMatrix2.cs               | 34 ++++++++++++++++++++++
 3 files changed, 112 insertions(+)
 create mode 100644 MergeSortedArray.cs
 create mode 100644 RemoveDuplicatesFromSortedArray.cs
 create mode 100644 SearchIn2DMatrix2.cs

diff --git a/MergeSortedArray.cs b/MergeSortedArray.cs
new file mode 100644
index 00000000..24ad75da
--- /dev/null
+++ b/MergeSortedArray.cs
@@ -0,0 +1,33 @@
+//Time Complexity: O(m + n)
+//Space Complexity: O(1)
+
+//Approach
+
+//Use three pointers (p1, p2, i) starting from the end of nums1, nums2 and the merged array.
+//While p2 >= 0, place the larger of nums1[p1] and nums2[p2] at nums1[i] (guarding p1 >= 0).
+//Decrement pointers accordingly; remaining nums1 elements are already in correct position.
+public class Solution
+{
+    public void Merge(int[] nums1, int m, int[] nums2, int n)
+    {
+        int p1 = m - 1;
+        int p2 = n - 1;
+        int i = m + n - 1;
+        while (p2 >= 0) //Because nums2 must be fully merged
+        {
+            if (p1 >= 0 && nums1[p1] > nums2[p2]) //Because p1 might be exhausted, but p2 not  be ignored
+            {
+                nums1[i--] = nums1[p1--];
+            }
+            else
+            {
+                nums1[i--] = nums2[p2--];
+            }
+        }
+    }
+}
+
+
+
+
+
diff --git a/RemoveDuplicatesFromSortedArray.cs b/RemoveDuplicatesFromSortedArray.cs
new file mode 100644
index 00000000..f6f8c02b
--- /dev/null
+++ b/RemoveDuplicatesFromSortedArray.cs
@@ -0,0 +1,45 @@
+// Time Complexity:
+// O(n)
+
+// Space Complexity:
+// O(1)
+
+//Approach
+// Keep slow pointer at index 0 , for loop Starts with index 1 ,
+// if the previous and the current elements are same increment count.
+// if the the elements are unequal reset the count to 1.
+// if count is less than 0 equal to 2 or k , update slow pointer with current vals.
+// Increment slow pointer.
+public class Solution
+{
+    public int RemoveDuplicates(int[] nums)
+    {
+        int slow = 1;
+        int count = 1;
+        for (int i = 1; i < nums.Length; i++)
+        {
+            if (nums[i] == nums[i - 1])
+            {
+                count++;
+            }
+            else
+            {
+                count = 1;
+            }
+            if (count <= 2)
+            {
+                nums[slow] = nums[i];
+                slow++;
+            }
+
+        }
+        return slow;
+    }
+}
+
+
+
+
+
+
+
diff --git a/SearchIn2DMatrix2.cs b/SearchIn2DMatrix2.cs
new file mode 100644
index 00000000..f054841a
--- /dev/null
+++ b/SearchIn2DMatrix2.cs
@@ -0,0 +1,34 @@
+public class Solution {
+
+    // Time Complexity:
+    // O(m + n)
+
+    // Space Complexity:
+    // O(1)
+
+    // Start from the top-right corner of the matrix.
+    // If the number is bigger, move left; if smaller, move down.
+    // Keep checking until you find the target or exit the matrix bounds.
+    public bool SearchMatrix(int[][] matrix, int target)
+    {
+        int m = matrix.Length;
+        int n = matrix[0].Length;
+        int r = 0; int c = n - 1;
+        while (r < m && c >= 0)
+        {
+            if (matrix[r][c] == target)
+            {
+                return true;
+            }
+            else if (target < matrix[r][c])
+            {
+                c--;
+            }
+            else
+            {
+                r++;
+            }
+        }
+        return false;
+    }
+}
\ No newline at end of file