《leetcode-go》插入法排序链表

使用插入法排序链表

注意：一定要保持链表的完整性，否则容易丢数据

package main

import "fmt"

type ListNode struct {
	Val  int
	Next *ListNode
}

func main() {
	a1 := new(ListNode)
	a1.Val = 1
	a2 := new(ListNode)
	a2.Val = 2
	a3 := new(ListNode)
	a3.Val = 3
	a1.Next = a2
	a2.Next = a3
	ret := sortList(a1)
	for ret != nil {
		fmt.Println(ret.Val)
		ret = ret.Next
		//break
	}
}

/**
 *
 * @param head ListNode类
 * @return ListNode类
 */
func sortList(head *ListNode) *ListNode {
	// write code here
	if head == nil || head.Next == nil {
		return head
	}
	newHead := &ListNode{
		Val:  0,
		Next: head,
	}
	lastNode := head
	node1 := head.Next
	for node1 != nil {
		node2 := newHead
		tmp := node1.Next
		lastTmp := node1
		for node2.Next != node1 {
			//从大到小
			if node1.Val > node2.Next.Val {
				node1.Next = node2.Next
				node2.Next = node1
				lastNode.Next = tmp
				lastTmp = lastNode
				break
			}
			//从小到大
			if node1.Val < node2.Next.Val {
				node1.Next = node2.Next
				node2.Next = node1
				lastNode.Next = tmp
				lastTmp = lastNode
				break
			}
			node2 = node2.Next
		}
		node1 = tmp
		lastNode = lastTmp
	}
	return newHead.Next
}