Adding splay tree implementation

Lobb Number.cpp

@@ -0,0 +1,41 @@
+// CPP Program to find Ln, m Lobb Number. 
+#include <bits/stdc++.h> 
+#define MAXN 109 
+using namespace std; 
+
+// Returns value of Binomial Coefficient C(n, k) 
+int binomialCoeff(int n, int k) 
+{ 
+	int C[n + 1][k + 1]; 
+
+	// Calculate value of Binomial Coefficient in 
+	// bottom up manner 
+	for (int i = 0; i <= n; i++) { 
+		for (int j = 0; j <= min(i, k); j++) { 
+			// Base Cases 
+			if (j == 0 || j == i) 
+				C[i][j] = 1; 
+
+			// Calculate value using previously stored values 
+			else
+				C[i][j] = C[i - 1][j - 1] + C[i - 1][j]; 
+		} 
+	} 
+
+	return C[n][k]; 
+} 
+
+// Return the Lm, n Lobb Number. 
+int lobb(int n, int m) 
+{ 
+	return ((2 * m + 1) * binomialCoeff(2 * n, m + n)) / (m + n + 1); 
+} 
+
+// Driven Program 
+int main() 
+{ 
+	int n = 5, m = 3; 
+	cout << lobb(n, m) << endl; 
+	return 0; 
+} 
+

SplayTree/SplayTree.cpp

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+#include <bits/stdc++.h> 
+using namespace std; 
+
+// An AVL tree node 
+class node 
+{ 
+	public: 
+	int key; 
+	node *left, *right; 
+}; 
+
+/* Helper function that allocates 
+a new node with the given key and 
+	NULL left and right pointers. */
+node* newNode(int key) 
+{ 
+	node* Node = new node(); 
+	Node->key = key; 
+	Node->left = Node->right = NULL; 
+	return (Node); 
+} 
+
+// A utility function to right 
+// rotate subtree rooted with y 
+// See the diagram given above. 
+node *rightRotate(node *x) 
+{ 
+	node *y = x->left; 
+	x->left = y->right; 
+	y->right = x; 
+	return y; 
+} 
+
+// A utility function to left 
+// rotate subtree rooted with x 
+// See the diagram given above. 
+node *leftRotate(node *x) 
+{ 
+	node *y = x->right; 
+	x->right = y->left; 
+	y->left = x; 
+	return y; 
+} 
+
+// This function brings the key at 
+// root if key is present in tree. 
+// If key is not present, then it 
+// brings the last accessed item at 
+// root. This function modifies the 
+// tree and returns the new root 
+node *splay(node *root, int key) 
+{ 
+	// Base cases: root is NULL or 
+	// key is present at root 
+	if (root == NULL || root->key == key) 
+		return root; 
+
+	// Key lies in left subtree 
+	if (root->key > key) 
+	{ 
+		// Key is not in tree, we are done 
+		if (root->left == NULL) return root; 
+
+		// Zig-Zig (Left Left) 
+		if (root->left->key > key) 
+		{ 
+			// First recursively bring the 
+			// key as root of left-left 
+			root->left->left = splay(root->left->left, key); 
+
+			// Do first rotation for root, 
+			// second rotation is done after else 
+			root = rightRotate(root); 
+		} 
+		else if (root->left->key < key) // Zig-Zag (Left Right) 
+		{ 
+			// First recursively bring 
+			// the key as root of left-right 
+			root->left->right = splay(root->left->right, key); 
+
+			// Do first rotation for root->left 
+			if (root->left->right != NULL) 
+				root->left = leftRotate(root->left); 
+		} 
+
+		// Do second rotation for root 
+		return (root->left == NULL)? root: rightRotate(root); 
+	} 
+	else // Key lies in right subtree 
+	{ 
+		// Key is not in tree, we are done 
+		if (root->right == NULL) return root; 
+
+		// Zag-Zig (Right Left) 
+		if (root->right->key > key) 
+		{ 
+			// Bring the key as root of right-left 
+			root->right->left = splay(root->right->left, key); 
+
+			// Do first rotation for root->right 
+			if (root->right->left != NULL) 
+				root->right = rightRotate(root->right); 
+		} 
+		else if (root->right->key < key)// Zag-Zag (Right Right) 
+		{ 
+			// Bring the key as root of 
+			// right-right and do first rotation 
+			root->right->right = splay(root->right->right, key); 
+			root = leftRotate(root); 
+		} 
+
+		// Do second rotation for root 
+		return (root->right == NULL)? root: leftRotate(root); 
+	} 
+} 
+
+// The search function for Splay tree. 
+// Note that this function returns the 
+// new root of Splay Tree. If key is 
+// present in tree then, it is moved to root. 
+node *search(node *root, int key) 
+{ 
+	return splay(root, key); 
+} 
+
+// A utility function to print 
+// preorder traversal of the tree. 
+// The function also prints height of every node 
+void preOrder(node *root) 
+{ 
+	if (root != NULL) 
+	{ 
+		cout<<root->key<<" "; 
+		preOrder(root->left); 
+		preOrder(root->right); 
+	} 
+} 
+
+/* Driver code*/
+int main() 
+{ 
+	node *root = newNode(100); 
+	root->left = newNode(50); 
+	root->right = newNode(200); 
+	root->left->left = newNode(40); 
+	root->left->left->left = newNode(30); 
+	root->left->left->left->left = newNode(20); 
+
+	root = search(root, 20); 
+	cout << "Preorder traversal of the modified Splay tree is \n"; 
+	preOrder(root); 
+	return 0; 
+} 
+
+// This code is contributed by Prithvi007
+