编写代码,以给定值x为基准将链表分割为两部分,所有小于x的节点排在大于或等于x的节点之前。
package test;
public class DivideList {
public Node divideList(Node head, int x){
if(head==null || head.next==null)
return head;
Node newHead = new Node(0);
newHead.next = head;
Node smallHead = new Node(0);
Node smallTail = smallHead;
Node largeHead = new Node(0);
Node largeHead = largeHead;
while(newHead.next != null){
if(newHead.next.val < x){
smallTail.next = newHead.next;
newHead.next = newHead.next.next;
smallTail = smallTail.next;
smallTail.next = null; //保持每次操纵尾部都指向null
}else{
largeTail.next = largeTail.next;
newHead.next = newHead.next.next;
largeTail = largeTail.next;
largeTail.next = null;
}
}
smallTail.next = largeHead.next;
return smallHead.next;
}
}