Remove Nodes From Linked List

Remove every node that has a strictly greater value somewhere after it in the singly linked list. Return the head of the remaining list, preserving the original order of the surviving nodes. An equal value to the right does not cause removal. Input and output arrays list node values from head to tail.

Example 1:

Input: head = [4,7,3,6,2]

Output: [7,6,2]

Explanation: Remove 4 because 7 is later, and remove 3 because 6 is later. The surviving nodes form 7 -> 6 -> 2.

Example 2:

Input: head = [5,5,3,3]

Output: [5,5,3,3]

Explanation: No node has a strictly greater value to its right. Equal later values do not count, so every node remains.

Example 3:

Input: head = [1,2,3,4]

Output: [4]

Explanation: Each of the first three nodes has a greater value later in the list. Only the final node, containing 4, remains.

Constraints:

• The list contains between 1 and 100000 nodes.
• 1 <= Node.val <= 100000