Create RemoveDuplicateInLinkedList.cpp

Cpp/RemoveDuplicateInLinkedList.cpp

@@ -0,0 +1,98 @@
+/* C++ Program to remove duplicates from a sorted linked list */
+#include <bits/stdc++.h>
+using namespace std;
+
+/* Link list node */
+class Node
+{
+	public:
+	int data;
+	Node* next;
+};
+
+/* The function removes duplicates from a sorted list */
+void removeDuplicates(Node* head)
+{
+	/* Pointer to traverse the linked list */
+	Node* current = head;
+
+	/* Pointer to store the next pointer of a node to be deleted*/
+	Node* next_next;
+
+	/* do nothing if the list is empty */
+	if (current == NULL)
+	return;
+
+	/* Traverse the list till last node */
+	while (current->next != NULL)
+	{
+	/* Compare current node with next node */
+	if (current->data == current->next->data)
+	{
+		/* The sequence of steps is important*/		
+		next_next = current->next->next;
+		free(current->next);
+		current->next = next_next;
+	}
+	else /* This is tricky: only advance if no deletion */
+	{
+		current = current->next;
+	}
+	}
+}
+
+/* UTILITY FUNCTIONS */
+/* Function to insert a node at the beginning of the linked 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;
+}
+
+/* Function to print nodes in a given linked list */
+void printList(Node *node)
+{
+	while (node!=NULL)
+	{
+		cout<<" "<<node->data;
+		node = node->next;
+	}
+}
+
+/* Driver program to test above functions*/
+int main()
+{
+	/* Start with the empty list */
+	Node* head = NULL;
+
+	/* Let us create a sorted linked list to test the functions
+	Created linked list will be 11->11->11->13->13->20 */
+	push(&head, 20);
+	push(&head, 13);
+	push(&head, 13);
+	push(&head, 11);
+	push(&head, 11);
+	push(&head, 11);									
+
+	cout<<"Linked list before duplicate removal ";
+	printList(head);
+
+	/* Remove duplicates from linked list */
+	removeDuplicates(head);
+
+	cout<<"\nLinked list after duplicate removal ";	
+	printList(head);			
+
+	return 0;
+}
+
+// This code is contributed by rathbhupendra