标签：
At the first sight of the problem, I misunderstood it as sort the former part of the list and then keep the original order of those nodes in the larger or equal to target value part. Thus, I sort the first part and get a wrong result.
Code:
/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */ public class Solution { public ListNode partition(ListNode head, int x) { ListNode cur = head; ListNode head1 = null, tail1 = null; ListNode head2 = null, tail2 = null; while(cur != null){ ListNode nex = cur.next; ListNode node = cur; if(node.val < x){ ListNode cur1 = head1; ListNode prev1 = null; while(cur1 != null && cur1.val < node.val) { prev1 = cur1; cur1 = cur1.next; } if(prev1 != null) prev1.next = node; else head1 = node; cur.next = cur1; if(cur1 == null) tail1 = node; } else{ ListNode cur2 = tail2; if(cur2 != null){ tail2.next = node; node.next = null; tail2 = node; } else{ head2 = node; tail2 = node; node.next = null; } } cur = nex; } if(tail1 != null) tail1.next = head2; if(head1 == null) return head2; return head1; } }
After a littile modification, we can the the right one:
/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { val = x; } * } */ public class Solution { public ListNode partition(ListNode head, int x) { ListNode cur = head; ListNode head1 = null, tail1 = null; ListNode head2 = null, tail2 = null; while(cur != null){ ListNode nex = cur.next; ListNode node = cur; if(node.val < x){ ListNode cur1 = tail1; if(cur1 != null){ tail1.next = node; node.next = null; tail1 = node; } else{ head1 = node; tail1 = node; node.next = null; } } else{ ListNode cur2 = tail2; if(cur2 != null){ tail2.next = node; node.next = null; tail2 = node; } else{ head2 = node; tail2 = node; node.next = null; } } cur = nex; } if(tail1 != null) tail1.next = head2; if(head1 == null) return head2; return head1; } }
Partition List; Linked List; Pointer;
标签：
原文地址：http://www.cnblogs.com/5683yue/p/5154537.html
