Merge pull request #138 from angha-varangaonkar/main

Add potd_09_10_2024.java

october_2024/potd_09_10_2024.java

@@ -0,0 +1,83 @@
+
+
+// User function Template for Java
+
+/*class Node
+
+class Node
+{
+   int data;
+   Node right,down;
+
+   Node(int data){
+       this.data = data;
+       right = null;
+       down = null;
+   }
+}
+*/
+/*Function should return the head of the 2D LL.*/
+class Solution {
+    static Node head;
+    static Node construct(int arr[][]) {
+        // Add your code here.
+        int n=arr.length;
+
+        if(n==1)
+        {
+            Node newnode =new Node(arr[0][0]); 
+            head=newnode;
+            return head;
+        }
+
+        Node newnode =new Node(arr[0][0]); 
+        head=newnode;
+
+        Node currnode=newnode;
+        Node firstnode=head;
+        Node secondnode=head;
+
+        for(int i=0;i<n;i++)
+        {
+
+            if(i>0)
+            {
+
+                Node newnode3=new Node(arr[i][0]);
+                firstnode.down=newnode3;
+
+                currnode=newnode3;
+                firstnode=firstnode.down;
+
+            }
+
+
+            for(int j=1;j<n;j++)
+            {
+                Node newnode2=new Node(arr[i][j]);
+                currnode.right=newnode2;
+                currnode=currnode.right;
+            }
+
+        }
+
+        firstnode = head;
+        while (firstnode.down != null) 
+        {
+            Node row1 = firstnode;
+            Node row2 = firstnode.down;
+
+            while (row1 != null && row2 != null) 
+            {
+                row1.down = row2;
+                row1 = row1.right;
+                row2 = row2.right;
+            }
+
+            firstnode = firstnode.down;
+        }
+
+
+        return head;
+    }
+}