Cut a part from a linked list?

Question

can I cut (delete) a portion from a Linked List by index? For example, if the input is "100", I want to delete the first 100 elements from a linked list. Currently, my code deletes them one by one.

public void remove(LinkedList<String> queue, int count){
    if (count > queue.size()) {
        System.out.println(ERROR);
        return;
    }

    for (int i = 0; i < count; i++) {
        queue.remove(0);
    }
}

No, there is no shortcut here - you must traverse the list to find the 100th element, so the time complexity is the same. You could skip deletion of every node and simply join the root the element 101 though. — Bohemian, Nov 09 '19 at 21:05

score 0 · Answer 1 · answered Nov 09 '19 at 20:32

0

you try with this:

splitList =  queue.subList(0, 100);

answered Nov 09 '19 at 20:32

Will that be faster? – Tropicano Nov 09 '19 at 20:33
subList returns List, not LinkedList. I can't cast it. – Tropicano Nov 09 '19 at 20:38
In what way does that *"**delete** the first 100 elements"*, as requested in the question? – Andreas Nov 09 '19 at 20:49
The problem is that I need to remove the elements faster than one by one. – Tropicano Nov 09 '19 at 20:58

score 0 · Answer 2 · edited Jun 20 '20 at 09:12

To delete the first 100 elements of a List, whether ArrayList, LinkedList, or any other kind of mutable list:

list.subList(0, 100).clear();

This is documented in the javadoc of subList():

This method eliminates the need for explicit range operations (of the sort that commonly exist for arrays). Any operation that expects a list can be used as a range operation by passing a subList view instead of a whole list. For example, the following idiom removes a range of elements from a list:
list.subList(from, to).clear();

Cut a part from a linked list?

2 Answers2