It is quite a basic problem. However I spent half an hour solving it and made two mistakes. Guess it‘s because I haven‘t written some fundamental data structures like linked list for a while and kind of get lost. I should practice these questions more.
public class Solution { public ListNode insertionSortList(ListNode head) { if (head == null || head.next == null) return head; ListNode cNode = head.next; ListNode prevcNode = head; while (cNode != null) { if (cNode.val <= head.val) { prevcNode.next = cNode.next; cNode.next = head; head = cNode; cNode = prevcNode.next; } else { ListNode tNode = head; while( tNode.next != cNode &&tNode.next.val < cNode.val) { tNode = tNode.next; } if(tNode.next == cNode) { prevcNode = cNode; cNode = cNode.next; } else { prevcNode.next = cNode.next; cNode.next = tNode.next; tNode.next = cNode; cNode = prevcNode.next; } } } return head; } }
Leetcode - Insertion Sort List
原文:http://blog.csdn.net/tspatial_thunder/article/details/40013855