splayTree

Java/Trees/splayTree.java

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+import java.util.Scanner;
+
+class splayTree {
+    class Node {
+        int key;
+        Node left, right;
+
+        public Node(int key) {
+            this.key = key;
+            left = right = null;
+        }
+    }
+
+    Node root;
+
+    public SplayTree() {
+        root = null;
+    }
+
+    public Node search(int key) {
+        return search(root, key);
+    }
+
+    private Node search(Node root, int key) {
+        if (root == null || root.key == key) {
+            return root;
+        }
+
+        if (root.key > key) {
+            return search(root.left, key);
+        } else {
+            return search(root.right, key);
+        }
+    }
+
+    public void insert(int key) {
+        root = insert(root, key);
+    }
+
+    private Node insert(Node root, int key) {
+        if (root == null) {
+            return new Node(key);
+        }
+
+        root = splay(root, key);
+
+        if (key < root.key) {
+            Node newNode = new Node(key);
+            newNode.right = root;
+            newNode.left = root.left;
+            root.left = null;
+            root = newNode;
+        } else if (key > root.key) {
+            Node newNode = new Node(key);
+            newNode.left = root;
+            newNode.right = root.right;
+            root.right = null;
+            root = newNode;
+        }
+
+        return root;
+    }
+
+    public void delete(int key) {
+        root = delete(root, key);
+    }
+
+    private Node delete(Node root, int key) {
+        Node temp;
+        if (root == null) {
+            return null;
+        }
+
+        root = splay(root, key);
+
+        if (key == root.key) {
+            if (root.left == null) {
+                temp = root;
+                root = root.right;
+            } else {
+                temp = root;
+                root = splay(root.left, key);
+                root.right = temp.right;
+            }
+            temp = null;
+        }
+
+        return root;
+    }
+
+    private Node splay(Node root, int key) {
+        if (root == null || root.key == key) {
+            return root;
+        }
+
+        if (key < root.key) {
+            if (root.left == null) {
+                return root;
+            }
+
+            if (key < root.left.key) {
+                root.left.left = splay(root.left.left, key);
+                root = rightRotate(root);
+            } else if (key > root.left.key) {
+                root.left.right = splay(root.left.right, key);
+                if (root.left.right != null) {
+                    root.left = leftRotate(root.left);
+                }
+            }
+            return root.left == null ? root : rightRotate(root);
+        } else {
+            if (root.right == null) {
+
+                return root;
+            }
+
+            if (key > root.right.key) {
+                root.right.right = splay(root.right.right, key);
+                root = leftRotate(root);
+            } else if (key < root.right.key) {
+                root.right.left = splay(root.right.left, key);
+                if (root.right.left != null) {
+                    root.right = rightRotate(root.right);
+                }
+            }
+
+            return root.right == null ? root : leftRotate(root);
+        }
+
+        private Node leftRotate(Node x) {
+            Node y = x.right;
+            x.right = y.left;
+            y.left = x;
+            return y;
+        }
+
+        private Node rightRotate(Node x) {
+            Node y = x.left;
+            x.left = y.right;
+            y.right = x;
+            return y;
+        }
+
+        public void inOrder() {
+            inOrder(root);
+        }
+
+        private void inOrder(Node root) {
+            if (root != null) {
+                inOrder(root.left);
+                System.out.print(root.key + " ");
+                inOrder(root.right);
+            }
+        }
+    }
+
+    public class Main {
+        public static void main(String[] args) {
+            SplayTree spt = new SplayTree();
+            Scanner sc = new Scanner(System.in);
+            int n = sc.nextInt();
+            for (int i = 0; i < n; i++) {
+                int num = sc.nextInt();
+                spt.insert(num);
+            }
+            spt.inOrder();
+        }
+    }
+}
+