Create Treap.java

Author: surajwakka

Coding/Treap.java

@@ -0,0 +1,79 @@
+import java.util.Random;
+
+class Node {
+    int key;
+    int priority;
+    Node left;
+    Node right;
+}
+
+public class Treap {
+    private Node createNode(int key) {
+        Node newNode = new Node();
+        newNode.key = key;
+        newNode.priority = new Random().nextInt();
+        newNode.left = newNode.right = null;
+        return newNode;
+    }
+
+    private Node rotateRight(Node y) {
+        Node x = y.left;
+        Node T2 = x.right;
+
+        x.right = y;
+        y.left = T2;
+
+        return x;
+    }
+
+    private Node rotateLeft(Node x) {
+        Node y = x.right;
+        Node T2 = y.left;
+
+        y.left = x;
+        x.right = T2;
+
+        return y;
+    }
+
+    private Node insert(Node root, int key) {
+        if (root == null) return createNode(key);
+
+        if (key <= root.key) {
+            root.left = insert(root.left, key);
+            if (root.left.priority > root.priority)
+                root = rotateRight(root);
+        } else {
+            root.right = insert(root.right, key);
+            if (root.right.priority > root.priority)
+                root = rotateLeft(root);
+        }
+
+        return root;
+    }
+
+    private void inorderTraversal(Node root) {
+        if (root != null) {
+            inorderTraversal(root.left);
+            System.out.print("(" + root.key + ", " + root.priority + ") ");
+            inorderTraversal(root.right);
+        }
+    }
+
+    public static void main(String[] args) {
+        Node root = null;
+
+        Treap treap = new Treap();
+        root = treap.insert(root, 50);
+        root = treap.insert(root, 30);
+        root = treap.insert(root, 20);
+        root = treap.insert(root, 40);
+        root = treap.insert(root, 70);
+        root = treap.insert(root, 60);
+        root = treap.insert(root, 80);
+
+        System.out.println("Inorder traversal of the treap:");
+        treap.inorderTraversal(root);
+        System.out.println();
+    }
+}