{"id":3767,"date":"2021-08-10T12:00:54","date_gmt":"2021-08-10T12:00:54","guid":{"rendered":"https:\/\/www.prepbytes.com\/blog\/?p=3767"},"modified":"2022-11-18T07:08:49","modified_gmt":"2022-11-18T07:08:49","slug":"delete-n-nodes-after-m-nodes-of-a-linked-list","status":"publish","type":"post","link":"https:\/\/prepbytes.com\/blog\/delete-n-nodes-after-m-nodes-of-a-linked-list\/","title":{"rendered":"Delete N nodes after M nodes of a Linked List"},"content":{"rendered":"

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In this tutorial, we are going to learn how to Delete N nodes after M nodes of a Linked List. Let\u2019s see the problem statement for a better understanding. <\/p>\n<\/p>\n

Problem Statement of Delete N nodes after M nodes of a Linked List<\/h3>\n

In this question, we are given a singly linked list, a value M and a value N. We have to delete N nodes after M nodes of the given list. This means that we will keep M nodes, delete N nodes, and will continue this till we reach the end of the linked list.<\/p>\n

Problem Statement Understanding of Delete N nodes after M nodes of a Linked List<\/h3>\n

Let the given list be 1 -> 2 -> 3 -> 4 -> 56 -> 45 -> 7 -> 8 and the value of M=2 and N=2. This means that after every 2 nodes, we will delete 2 nodes. <\/p>\n

So, in the first step, our linked list will be 1 -> 2 -> 56 -> 45 -> 7 -> 8. As we can see, we have removed the 3rd<\/sup> and 4th<\/sup> nodes from the list. Now, in the second step, our linked list will be 1 -> 2 -> 56 -> 45. Now, we have reached the tail of the list. <\/p>\n

So, the final linked list is 1 – > 2 – > 56 – > 45.<\/p>\n

Input:<\/strong> M=2, N=2 <\/p>\n

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Output:<\/strong><\/p>\n

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Explanation:<\/strong> As the value of M is 2 and the value of N is 2, we will retain 2 nodes and delete 2 nodes till we reach the end of the list. <\/p>\n

This is an interesting question. It is not a complex one, but we have to look out for all the edge cases. Let us have a glance at the approach.<\/p>\n

Approach on how to Delete N nodes after M nodes of a Linked List <\/h3>\n

We are going to make use of list traversal here. First, we will skip M nodes. Now, if we reach the end of the list, then we will terminate the method, else, we will store the address of the Mth<\/sup> node in the current and temp will point to the (M+1)th<\/sup> node which is next of current. Now, we will traverse the next N nodes, and increment temp. In the end, we will make the Mth<\/sup> node point to the temp, and temp will become our new current. <\/p>\n

Algorithm of how to Delete N nodes after M nodes of a Linked List<\/h3>\n
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  • Create a node current, and make it point to the head.<\/li>\n
  • Traverse through the list till the end is reached.<\/li>\n
  • Skip M nodes. We can do this with the help of a for a loop. In every iteration, do current = current -> next.<\/li>\n
  • Now, if the current becomes NULL, it means that we have reached the end of the list. We will terminate the method.<\/li>\n
  • Else, store the next current in temp. Write a for loop that runs N times, and increment temp by 1 in each iteration.<\/li>\n
  • After the loop, make the current point to temp.<\/li>\n
  • The temp will become our new current.<\/li>\n<\/ul>\n

    Dry Run on how to Delete N nodes after M nodes of a Linked List <\/h3>\n

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    Code Implementation<\/h3>\n\t\t\t\t\t\t