Using insertion sort on a singly linked list

Question

So I have an assignment where I\'m giving a random list of number and I need to sort them using insertion sort. I must use a singly linked list. I looked around at other posts b

Answer 1

Here is the Java Implementation of Insertion Sort on Linked List:

• Time Complexity: O(n^2)
• Space Complexity: O(1) - Insertion sort is In-Place sorting algorithm

class Solution 
{
    public ListNode insertionSortList(ListNode head)
    {
        // Initialize partially sorted list
        ListNode dummy = new ListNode(0), prev = dummy, current = head;

        while(current != null)
        {
            if(prev.val > current.val)
                prev = dummy;

            // Find the right place to insert current node
            while(prev.next != null && prev.next.val < current.val)
                prev = prev.next;

            // Insert current between prev and prev.next
            ListNode nextNode = current.next;
            current.next = prev.next;
            prev.next = current;
            current = nextNode;
        }
        return dummy.next;
    }
}