Insertion Sort List

Insertion Sort List

Sort a linked list using insertion sort.

Given 1->3->2->0->null, return 0->1->2->3->null.

/**
 * Definition for ListNode.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int val) {
 *         this.val = val;
 *         this.next = null;
 *     }
 * }
 */ 
public class Solution {
    /**
     * @param head: The first node of linked list.
     * @return: The head of linked list.
     */
    public ListNode insertionSortList(ListNode head) {
        // write your code here
        ListNode dummy = new ListNode(Integer.MIN_VALUE);
        
        while (head != null) {
            ListNode curr = head;
            ListNode insert = dummy;
            while (insert.next != null && insert.next.val <= curr.val) {
                insert = insert.next;
            }
            head = head.next;
            curr.next = insert.next;
            insert.next = curr;
        }
        
        return dummy.next;
    }
}