Added codes for 22 March"

GeeksForGeeks/March/22-3-24/GFG.java

@@ -0,0 +1,148 @@
+//{ Driver Code Starts
+//Initial Template for Java
+
+import java.util.LinkedList; 
+import java.util.Queue; 
+import java.io.*;
+import java.util.*;
+
+class Node{
+    int data;
+    Node left;
+    Node right;
+    Node(int data){
+        this.data = data;
+        left=null;
+        right=null;
+    }
+}
+
+class GfG {
+
+    static Node buildTree(String str){
+
+        if(str.length()==0 || str.charAt(0)=='N'){
+            return null;
+        }
+
+        String ip[] = str.split(" ");
+        // Create the root of the tree
+        Node root = new Node(Integer.parseInt(ip[0]));
+        // Push the root to the queue
+
+        Queue<Node> queue = new LinkedList<>(); 
+
+        queue.add(root);
+        // Starting from the second element
+
+        int i = 1;
+        while(queue.size()>0 && i < ip.length) {
+
+            // Get and remove the front of the queue
+            Node currNode = queue.peek();
+            queue.remove();
+
+            // Get the current node's value from the string
+            String currVal = ip[i];
+
+            // If the left child is not null
+            if(!currVal.equals("N")) {
+
+                // Create the left child for the current node
+                currNode.left = new Node(Integer.parseInt(currVal));
+                // Push it to the queue
+                queue.add(currNode.left);
+            }
+
+            // For the right child
+            i++;
+            if(i >= ip.length)
+                break;
+
+            currVal = ip[i];
+
+            // If the right child is not null
+            if(!currVal.equals("N")) {
+
+                // Create the right child for the current node
+                currNode.right = new Node(Integer.parseInt(currVal));
+
+                // Push it to the queue
+                queue.add(currNode.right);
+            }
+            i++;
+        }
+
+        return root;
+    }
+    static void printInorder(Node root)
+    {
+        if(root == null)
+            return;
+
+        printInorder(root.left);
+        System.out.print(root.data+" ");
+
+        printInorder(root.right);
+    }
+
+	public static void main (String[] args) throws IOException{
+	        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+
+	        int t=Integer.parseInt(br.readLine());
+
+	        while(t > 0)
+	        {
+	            String s = br.readLine();
+    	    	Node root = buildTree(s);
+        	    Tree g = new Tree();
+			    ArrayList <Integer> res = g.diagonalSum(root);
+			    for (Integer num : res) System.out.print(num + " ");
+			    System.out.println();
+                t--;
+
+        }
+    }
+
+}
+
+
+// } Driver Code Ends
+
+
+/*Complete the function below
+Node is as follows:
+class Node{
+    int data;
+    Node left,right;
+    Node(int d){
+        data=d;
+        left=right=null;
+    }
+}
+*/
+class Tree 
+{
+    public static void diagonalSumUtil(Node root, int diagonal, Map<Integer, Integer> map)
+    {
+        // base case: empty tree
+        if (root == null)
+            return;
+
+        map.put(diagonal, map.getOrDefault(diagonal, 0) + root.data);
+        diagonalSumUtil(root.left, diagonal + 1, map);
+        diagonalSumUtil(root.right, diagonal, map);
+    }
+
+    public static ArrayList <Integer> diagonalSum(Node root)
+    {
+        ArrayList <Integer> res = new ArrayList <Integer> (0);
+        Map<Integer, Integer> map = new HashMap<>();
+        diagonalSumUtil(root, 0, map);
+
+        for (Integer key : map.values())
+            res.add(key);
+
+        return res;
+    }
+}

GeeksForGeeks/March/22-3-24/README.md

@@ -0,0 +1,2 @@
+Time complexity - O(n * logn)
+Space complexity - O(n)

LeetCode/March/22-3-24/README.md

@@ -0,0 +1,2 @@
+Time complexity - O(n)
+Space complexity - O(1)

LeetCode/March/22-3-24/Solution.java

@@ -0,0 +1,55 @@
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     int val;
+ *     ListNode next;
+ *     ListNode() {}
+ *     ListNode(int val) { this.val = val; }
+ *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
+ * }
+ */
+class Solution 
+{
+    public boolean isPalindrome(ListNode head) 
+    {
+        ListNode slow = head;
+        ListNode fast = head;
+
+        while (fast != null && fast.next != null) 
+        {
+            slow = slow.next;
+            fast = fast.next.next;
+        }
+
+        if (fast != null)
+            slow = slow.next;
+
+        slow = reverseList(slow);
+
+        while (slow != null) 
+        {
+            if (slow.val != head.val)
+                return false;
+
+            slow = slow.next;
+            head = head.next;
+        }
+
+        return true;
+    }
+
+    private ListNode reverseList(ListNode head) 
+    {
+        ListNode prev = null;
+
+        while (head != null) 
+        {
+            ListNode next = head.next;
+            head.next = prev;
+            prev = head;
+            head = next;
+        }
+
+        return prev;
+    }
+}