Insertion Sort List

题目：

Sort a linked list using insertion sort.

分析：

无

解法：

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(0);
        while (head != null) {
            ListNode curr = dummy;
            while (curr.next != null && curr.next.val < head.val) {
                curr = curr.next;
            }
            ListNode temp = head;
            head = head.next;
            temp.next = curr.next;
            curr.next = temp;
        }
        return dummy.next;
    }
}