Merge pull request #338 from neha030/dev9

Remove all Duplicates from Linkedlist added

Author: smv1999

Data Structures/Linked Lists/Remove_all_Duplicates_from_Linnkedlist.cpp

@@ -0,0 +1,98 @@
+/*
+Given the Sorted Linked list head which contain duplicates, the task is
+to delete all the duplicate and make linked list such that every element
+appear just one time.
+Example:
+Original Linked list : 1 1 2 2 3
+Answer : 1 2 3
+*/
+
+#include <bits/stdc++.h>
+using namespace std;
+
+// A linked list node
+class Node
+{
+    public:
+    int data;
+    Node *next;
+};
+
+// Utility function to create a new Node
+void push(Node **head, int n_data)
+{
+    Node *newdata = new Node();
+    newdata->data = n_data;
+    newdata->next = (*head);
+    (*head) = newdata;
+}
+
+// Function to print nodes in a given linked list. 
+void printlinkedlist(Node *temp)
+{
+    while (temp != NULL)
+    {
+        cout << "->" << temp->data;
+        temp = temp->next;
+    }
+}
+
+// Function to delete duplicate nodes
+Node *delete_duplicates(Node *head)
+{
+    //initalize current to head
+    Node *curr = head;
+    // when curr and curr->next is not NULL
+    // enter the loop
+    while (curr && curr->next)
+    {
+        // if the adjacent nodes are found to be equal
+        if (curr->next->data == curr->data)
+        {
+            // then point the curr->next to one step ahead
+            // to the existing pointer.
+            curr->next = curr->next->next;
+        }
+        else
+        {
+            // Until the current and current->next values are 
+            // not same, keep updating current
+            curr = curr->next;
+        }
+    }
+    return head;
+}
+int main()
+{
+    Node *head = NULL;
+    int n;
+    cout << "Enter number of Elements:";
+    cin >> n;
+    cout << "Enter elements:";
+    for (int i = 0; i < n; i++)
+    {
+        int a;
+        cin >> a;
+        push(&head, a);
+    }
+    cout <<"Original Linked list:\n";
+    printlinkedlist(head);
+    cout <<"\nNew Linked List:\n";
+    head = delete_duplicates(head);
+    printlinkedlist(head);
+}
+
+/*
+Sample Input:
+Enter number of Elements:5
+Enter elements:1 1 2 2 3
+
+Sample Output:
+Original Linked list:
+->3->2->2->1->1
+New Linked List:
+->3->2->1
+
+Time-Complexity: O(n)
+Space-Complexity: O(1)
+*/