Update Remove_all_Duplicates_from_Linnkedlist.cpp

Comments added

Author: neha030

Data Structures/Linked Lists/Remove_all_Duplicates_from_Linnkedlist.cpp

@@ -10,19 +10,24 @@ 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)
@@ -31,17 +36,27 @@ void printlinkedlist(Node *temp)
         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;
         }
     }
@@ -80,4 +95,4 @@ New Linked List:
 
 Time-Complexity: O(n)
 Space-Complexity: O(1)
-*/
+*/