Create deletelinkedlist.cpp

Java/deletelinkedlist.cpp

@@ -0,0 +1,133 @@
+// C++ program to delete a given key from
+// linked list.
+#include <bits/stdc++.h>
+using namespace std;
+
+// Structure for a node
+class Node {
+public:
+	int data;
+	Node* next;
+};
+
+// Function to insert a node at the
+// beginning of a Circular linked list
+void push(Node** head_ref, int data)
+{
+
+	// Create a new node and make head
+	// as next of it.
+	Node* ptr1 = new Node();
+	ptr1->data = data;
+	ptr1->next = *head_ref;
+
+	// If linked list is not NULL then
+	// set the next of last node
+	if (*head_ref != NULL) {
+
+		// Find the node before head and
+		// update next of it.
+		Node* temp = *head_ref;
+		while (temp->next != *head_ref)
+			temp = temp->next;
+		temp->next = ptr1;
+	}
+	else
+
+		// For the first node
+		ptr1->next = ptr1;
+
+	*head_ref = ptr1;
+}
+
+// Function to print nodes in a given
+// circular linked list
+void printList(Node* head)
+{
+	Node* temp = head;
+	if (head != NULL) {
+		do {
+			cout << temp->data << " ";
+			temp = temp->next;
+		} while (temp != head);
+	}
+
+	cout << endl;
+}
+
+// Function to delete a given node
+// from the list
+void deleteNode(Node** head, int key)
+{
+
+	// If linked list is empty
+	if (*head == NULL)
+		return;
+
+	// If the list contains only a
+	// single node
+	if ((*head)->data == key && (*head)->next == *head) {
+		free(*head);
+		*head = NULL;
+		return;
+	}
+
+	Node *last = *head, *d;
+
+	// If head is to be deleted
+	if ((*head)->data == key) {
+
+		// Find the last node of the list
+		while (last->next != *head)
+			last = last->next;
+
+		// Point last node to the next of
+		// head i.e. the second node
+		// of the list
+		last->next = (*head)->next;
+		free(*head);
+		*head = last->next;
+		return;
+	}
+
+	// Either the node to be deleted is
+	// not found or the end of list
+	// is not reached
+	while (last->next != *head && last->next->data != key) {
+		last = last->next;
+	}
+
+	// If node to be deleted was found
+	if (last->next->data == key) {
+		d = last->next;
+		last->next = d->next;
+		free(d);
+	}
+	else
+		cout << "no such keyfound";
+}
+
+// Driver code
+int main()
+{
+	// Initialize lists as empty
+	Node* head = NULL;
+
+	// Created linked list will be
+	// 2->5->7->8->10
+	push(&head, 2);
+	push(&head, 5);
+	push(&head, 7);
+	push(&head, 8);
+	push(&head, 10);
+
+	cout << "List Before Deletion: ";
+	printList(head);
+
+	deleteNode(&head, 7);
+
+	cout << "List After Deletion: ";
+	printList(head);
+
+	return 0;
+}