I'm writing an extra removeRange() method that except a start index and end index as parameters. I've passed all the conditions except when the number of nodes equals the range from start to end.

example my linked list contains:

1 -> 2 -> 3

after the method removeRange(0,2) is called:

list should become null, since from 0 to 2, the count is 3 and there are also 3 elements in my list.

look at the picture for a better idea of what's going on if you can.

Code:

public void removeRange(int start, int end) {
    if(start < 0 || end < 0) {
        throw new IllegalArgumentException();
    }
    if(start == 0 && end == 0) {
        front = front.next;
    } else if (start == 0 && end == 1) {
        front = front.next.next;
    } else {
        ListNode head = front;
        for(int i = 0; i < start-1;i++) {
            head = head.next;
        }
        ListNode tail = front;
        for(int i = 0; i < end;i++) {
            tail = tail.next;
        }
        head.next = tail.next;
    }
}

Assuming that your tail.next == null then you still need to set front = head as you have done similarly in your previous cases where you update front.

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