# Delete all the nodes from the list that are greater than x

• Difficulty Level : Easy
• Last Updated : 05 Jul, 2022

Given a linked list, the problem is to delete all the nodes from the list that are greater than the specified value x. Examples:

```Input : list: 7->3->4->8->5->1
x = 6
Output : 3->4->5->1

Input : list: 1->8->7->3->7->10
x = 7
Output : 1->7->3->7```

Approach: This is mainly a variation of the post which deletes first occurrence of a given key. We need to first check for all occurrences at head node which are greater than ‘x’, delete them and change the head node appropriately. Then we need to check for all occurrences inside a loop and delete them one by one.

## CPP

 `// C++ implementation to delete all the nodes from the list``// that are greater than the specified value x``#include ``  ` `using` `namespace` `std;``  ` `// structure of a node``struct` `Node {``    ``int` `data;``    ``Node* next;``};``  ` `// function to get a new node``Node* getNode(``int` `data)``{``    ``Node* newNode = ``new` `Node;``    ``newNode->data = data;``    ``newNode->next = NULL;``    ``return` `newNode;``}``  ` `// function to delete all the nodes from the list``// that are greater than the specified value x``void` `deleteGreaterNodes(Node** head_ref, ``int` `x)``{``    ``Node *temp = *head_ref, *prev;``  ` `    ``// If head node itself holds the value greater than 'x'``    ``if` `(temp != NULL && temp->data > x) {``        ``*head_ref = temp->next; ``// Changed head``        ``free``(temp); ``// free old head``        ``temp = *head_ref; ``// Change temp``    ``}``  ` `    ``// Delete occurrences other than head``    ``while` `(temp != NULL) {``  ` `        ``// Search for the node to be deleted,``        ``// keep track of the previous node as we``        ``// need to change 'prev->next'``        ``while` `(temp != NULL && temp->data <= x) {``            ``prev = temp;``            ``temp = temp->next;``        ``}``  ` `        ``// If required value node was not present``        ``// in linked list``        ``if` `(temp == NULL)``            ``return``;``  ` `        ``// Unlink the node from linked list``        ``prev->next = temp->next;``  ` `        ``delete` `temp; ``// Free memory``  ` `        ``// Update Temp for next iteration of``        ``// outer loop``        ``temp = prev->next;``    ``}``}``  ` `// function to a print a linked list``void` `printList(Node* head)``{``    ``while` `(head) {``        ``cout << head->data << ``" "``;``        ``head = head->next;``    ``}``}``  ` `// Driver program to test above``int` `main()``{``    ``// Create list: 7->3->4->8->5->1``    ``Node* head = getNode(7);``    ``head->next = getNode(3);``    ``head->next->next = getNode(4);``    ``head->next->next->next = getNode(8);``    ``head->next->next->next->next = getNode(5);``    ``head->next->next->next->next->next = getNode(1);``  ` `    ``int` `x = 6;``  ` `    ``cout << ``"Original List: "``;``    ``printList(head);``  ` `    ``deleteGreaterNodes(&head, x);``  ` `    ``cout << ``"\nModified List: "``;``    ``printList(head);``  ` `    ``return` `0;``}`

## Java

 `// Java implementation to delete all nodes from the list``// that are greater than the specified value x``import` `java.io.*;` `class` `Node {``    ``int` `data;``    ``Node next;``}` `class` `GFG {` `    ``// Function to get a new node.``    ``public` `Node getNode(``int` `data)``    ``{``        ``Node new_node = ``new` `Node();``        ``new_node.data = data;``        ``new_node.next = ``null``;``        ``return` `new_node;``    ``}` `    ``// Function to print linked list.``    ``public` `void` `printList(Node head)``    ``{``        ``Node temp = head;``        ``while` `(temp != ``null``) {``            ``System.out.print(temp.data + ``" "``);``            ``temp = temp.next;``        ``}``    ``}` `    ``// Functions to delete nodes which have greater value``    ``// than x.``    ``public` `Node deleteGreaterNodes(Node head, ``int` `x)``    ``{``        ``Node temp = head;``      ` `        ``// while loop takes care if head node value greater``        ``// than x.``        ``while` `(temp != ``null` `&& temp.data > x) {``            ``temp = temp.next;``            ``head = temp; ``// new head.``        ``}``        ``temp = head;``        ``Node prev = temp;``      ` `        ``// nodes other than head having value greater than x``        ``while` `(temp != ``null``) {``            ``while` `(temp != ``null` `&& temp.data <= x) {``                ``prev = temp;``                ``temp = temp.next;``            ``}``            ``if` `(temp == ``null``) {``                ``return` `head;``            ``}``            ``// if there is a node in middle which has``            ``// greater value, we point the node to the next``            ``// node.``            ``prev.next = temp.next;``            ``// update temp for next iteration of loop.``            ``temp = prev.next;``        ``}``        ``return` `head;``    ``}` `    ``public` `static` `void` `main(String[] args)``    ``{` `        ``GFG list = ``new` `GFG();` `        ``// Create list: 7->3->4->8->5->1.``        ``Node head = list.getNode(``7``);``        ``head.next = list.getNode(``3``);``        ``head.next.next = list.getNode(``4``);``        ``head.next.next.next = list.getNode(``8``);``        ``head.next.next.next.next = list.getNode(``5``);``        ``head.next.next.next.next.next = list.getNode(``1``);` `        ``System.out.print(``"Original List: "``);``        ``list.printList(head);` `        ``int` `x = ``6``;` `        ``head = list.deleteGreaterNodes(head, x);``        ``System.out.print(``"\nModified List: "``);``        ``list.printList(head);``    ``}``}` `// This code is contributed by lokesh (lokeshmvs21).`

Output:

```Original List: 7 3 4 8 5 1
Modified List: 3 4 5 1```

Time Complexity: O(n).

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