reverseLinkedlistRecursively.go

package main

import "fmt"

type node struct {
	data            int
	nextnodepointer *node
}

type linkedList struct {
	headnode *node
	length   int
}

func (l *linkedList) insertAtTheEnd(value int) {
	n := node{value, nil}
	if l.length == 0 {
		l.headnode = &n
		l.length++
		return
	}
	ptr := l.headnode
	for i := 0; i < l.length; i++ {
		if ptr.nextnodepointer == nil {
			ptr.nextnodepointer = &n
			l.length++
			return
		}
		ptr = ptr.nextnodepointer
	}
}

func (l linkedList) printData() {
	toPrint := l.headnode
	for l.length != 0 {
		fmt.Printf("%d\t", toPrint.data)
		l.length--
		toPrint = toPrint.nextnodepointer
	}
	fmt.Println("")
}

func (l *linkedList) prepend(n *node) {
	second := l.headnode
	l.headnode = n
	l.headnode.nextnodepointer = second
	l.length++
}

func (l *linkedList) reverseRecursive(n *node) {
	var current *node = n
	if current == nil {
		return
	}
	if current.nextnodepointer == nil {
		l.headnode = current
		return
	}
	n = n.nextnodepointer
	l.reverseRecursive(n)
	current.nextnodepointer.nextnodepointer = current
	current.nextnodepointer = nil
}

func main() {
	myList := linkedList{}
	myList.insertAtTheEnd(10)
	myList.insertAtTheEnd(20)
	myList.insertAtTheEnd(30)
	myList.insertAtTheEnd(40)
	myList.insertAtTheEnd(50)
	n1 := &node{data: 100}
	n2 := &node{data: 200}
	myList.prepend(n1)
	myList.prepend(n2)
	myList.printData() // 200 100 50 40 30 20 10
	myList.reverseRecursive(n2)
	myList.printData() // 10 20 30 40 50 100 200
}