Length of Linked List

insertionInLinkedList.cpp

@@ -0,0 +1,114 @@
+// Alternate method to declare the class
+// in order to minimize the
+// memory allocation work
+
+#include <bits/stdc++.h>
+using namespace std;
+
+class node {
+public:
+	int data;
+	node* next;
+
+	// A constructor is called here
+	node(int value)
+	{
+
+		// It automatic assigns the
+		// value to the data
+		data = value;
+
+		// Next pointer is pointed to NULL
+		next = NULL;
+	}
+};
+
+// Function to insert an element
+// at head position
+void insertathead(node*& head, int val)
+{
+	node* n = new node(val);
+	n->next = head;
+	head = n;
+}
+
+// Function to insert a element
+// at a specified position
+void insertafter(node* head, int key, int val)
+{
+	node* n = new node(val);
+	if (key == head->data) {
+		n->next = head->next;
+		head->next = n;
+		return;
+	}
+
+	node* temp = head;
+	while (temp->data != key) {
+		temp = temp->next;
+		if (temp == NULL) {
+			return;
+		}
+	}
+	n->next = temp->next;
+	temp->next = n;
+}
+
+// Function to insert an
+// element at the end
+void insertattail(node*& head, int val)
+{
+	node* n = new node(val);
+	if (head == NULL) {
+		head = n;
+		return;
+	}
+
+	node* temp = head;
+	while (temp->next != NULL) {
+		temp = temp->next;
+	}
+	temp->next = n;
+}
+
+// Function to print the
+// singly linked list
+void print(node*& head)
+{
+	node* temp = head;
+
+	while (temp != NULL) {
+		cout << temp->data << " -> ";
+		temp = temp->next;
+	}
+	cout << "NULL" << endl;
+}
+
+// Main function
+int main()
+{
+
+	// Declaring an empty linked list
+	node* head = NULL;
+
+	insertathead(head, 1);
+	insertathead(head, 2);
+	cout << "After insertion at head: ";
+	print(head);
+	cout << endl;
+
+	insertattail(head, 4);
+	insertattail(head, 5);
+	cout << "After insertion at tail: ";
+	print(head);
+	cout << endl;
+
+	insertafter(head, 1, 2);
+	insertafter(head, 5, 6);
+	cout << "After insertion at a given position: ";
+	print(head);
+	cout << endl;
+
+	return 0;
+}
+// contributed by divyanshmishra101010

lengthOfLinkedList.cpp

@@ -0,0 +1,61 @@
+// Tail Recursive C++ program to find length
+// or count of nodes in a linked list
+#include <bits/stdc++.h>
+using namespace std;
+
+/* Link list node */
+class Node {
+public:
+	int data;
+	Node* next;
+};
+
+/* Given a reference (pointer to pointer) to the head
+of a list and an int, push a new node on the front
+of the list. */
+void push(Node** head_ref, int new_data)
+{
+	/* allocate node */
+	Node* new_node = new Node();
+
+	/* put in the data */
+	new_node->data = new_data;
+
+	/* link the old list off the new node */
+	new_node->next = (*head_ref);
+
+	/* move the head to point to the new node */
+	(*head_ref) = new_node;
+}
+// A tail recursive function to count the nodes of a linked
+// list
+// default value of the count is used as zero
+int getCount(Node* head, int count = 0)
+{
+	// base case
+	if (head == NULL)
+		return count;
+	// move the pointer to next node and increase the count
+	return getCount(head->next, count + 1);
+}
+
+/* Driver code*/
+int main()
+{
+	/* Start with the empty list */
+	Node* head = NULL;
+
+	/* Use push() to construct below list
+	1->2->1->3->1 */
+	push(&head, 1);
+	push(&head, 3);
+	push(&head, 1);
+	push(&head, 2);
+	push(&head, 1);
+
+	// Function call
+	cout << "Count of nodes is " << getCount(head);
+	return 0;
+}
+
+// This is code is contributed by Abhijeet Kumar