Java dsa-Tree

Tree/BST.java

@@ -0,0 +1,172 @@
+package Java_DSA.Tree;
+
+import java.util.Scanner;
+
+public class BST {
+    private static Node root;
+
+    private static class Node{
+        int data;
+        Node left;
+        Node right;
+
+        public Node(int data){
+            this.data = data;
+        }
+    }
+
+    public static Node insert(Node root,int val){
+        Node temp = new Node(val);
+        if(root == null){
+            root = temp;
+            return root;
+        }
+        if(val < root.data){
+            root.left = insert(root.left,val);
+        }
+        else{
+            root.right = insert(root.right,val);
+        }
+
+        return root;
+    }
+
+    public static void insert(int val){
+        Node p = root;
+        Node ptr = null;
+        while(p != null){
+            ptr = p;
+            if(val < p.data){
+                p = p.left;
+            }
+            else if(val > p.data){
+                p = p.right;
+            }
+            else{
+                System.out.println(val +" is already present in tree.");
+                return;
+            }
+        }
+        Node temp = new Node(val);
+
+        if(ptr == null)
+            root = temp;
+        else if(val < ptr.data)
+            ptr.left = temp;
+        else
+            ptr.right = temp;
+    }
+
+    public static void inorder(Node root){
+        if(root == null){
+            return;
+        }
+        inorder(root.left);
+        System.out.print(root.data + " ");
+        inorder(root.right);
+    }
+
+    public static boolean search(Node root,int key){
+        if(root == null){
+            return false;
+        }
+        if(key < root.data){
+            return search(root.left,key);
+        }
+        else if(key == root.data){
+            return true;
+        }
+        else{
+            return search(root.right,key);
+        }
+    }
+
+    public static Node delete(Node root,int val){
+        if(search(root,val)) {
+            if (val < root.data) {
+                root.left = delete(root.left, val);
+            } else if (val > root.data) {
+                root.right = delete(root.right, val);
+            } else {  //root.data == val
+                if (root.left == null && root.right == null) {
+                    return null;
+                }
+                if (root.left == null)
+                    return root.right;
+                else if (root.right == null)
+                    return root.left;
+                else {
+                    Node IS = inorderSuccesser(root.right);
+                    root.data = IS.data;
+                    root.right = delete(root.right, IS.data);
+                }
+            }
+        }
+        else
+            System.out.println("Data is not present to delete.");
+
+        return root;
+    }
+
+    public static Node inorderSuccesser(Node root){
+        while(root.left != null){
+            root = root.left;
+        }
+        return root;
+    }
+
+    public static int countNode(Node root){
+        if(root == null){
+            return 0;
+        }
+        int leftNode = countNode(root.left);
+        int rightNode = countNode(root.right);
+        return leftNode + rightNode + 1;
+    }
+
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        //Node root = null;
+        boolean flag = true;
+        System.out.println("1)Insert data.\n2)Search.\n3)Delete.\n4)Display inorder.\n5)Count the nodes.\n6)Exit.");
+        while(flag){
+            System.out.println("Enter your choice : ");
+            int choice = sc.nextInt();
+            switch (choice){
+                case 1->{
+                    System.out.println("Enter data to insert : ");
+                    int data = sc.nextInt();
+                    //root = insert(root,data);
+                    insert(data);
+                }
+                case 2->{
+                    System.out.println("Enter data to search : ");
+                    int searchValue = sc.nextInt();
+                    if(search(root,searchValue))
+                        System.out.println("Found");
+                    else
+                        System.out.println("Not found");
+                }
+                case 3->{
+                    System.out.println("Enter data to delete : ");
+                    int dataToDelete = sc.nextInt();
+                    root = delete(root,dataToDelete);
+                }
+                case 4->{
+                    inorder(root);
+                    System.out.println();
+                }
+                case 5->{
+                    System.out.println("Number of nodes : "+countNode(root));
+                    System.out.println();
+                }
+                case 6->{
+                    flag = false;
+                }
+                default -> {
+                    System.out.println("Invalid choice..!");
+                }
+            }
+        }
+    }
+}

Tree/BinaryTree.java

@@ -0,0 +1,73 @@
+package Java_DSA.Tree;
+
+import java.util.Scanner;
+
+public class BinaryTree<Private> {
+    private static Node left;
+    private static Node right;
+
+    private static class Node{
+        int data;
+        Node left;
+        Node right;
+
+        public Node(int data){
+            this.data = data;
+        }
+    }
+
+    static int index = -1;
+    public static Node createTree(int[] nodes){
+    index++;
+    if(nodes[index] == -1){
+        return null;
+    }
+        Node temp = new Node(nodes[index]);
+        temp.left = createTree(nodes);
+        temp.right = createTree(nodes);
+
+        return temp;
+    }
+
+    public static void preorder(Node root){
+        if(root == null){
+            return;
+        }
+        System.out.print(root.data + " ");
+        preorder(root.left);
+        preorder(root.right);
+    }
+
+    public static void inorder(Node root){
+        if(root == null){
+            return;
+        }
+        inorder(root.left);
+        System.out.print(root.data + " ");
+        inorder(root.right);
+    }
+
+    public static void postorder(Node root){
+        if(root == null){
+            return;
+        }
+        postorder(root.left);
+        postorder(root.right);
+        System.out.print(root.data + " ");
+
+    }
+
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int[] nodes = {4,7,2,-1,-1,3,9,-1,-1,10,-1,-1,5,-1,15,11,-1,-1,14,-1,-1};
+        Node root = createTree(nodes);
+        System.out.println("Preorder traversal ");
+        preorder(root);
+        System.out.println();
+        System.out.println("Inorder traversal ");
+        inorder(root);
+        System.out.println();
+        System.out.println("postorder traversal ");
+        postorder(root);
+    }
+}