Reverse a linked list in Go (Golang)

Overview

The objective is to reverse a given linked list.

Eg

Input: 3->2->1
Output: 1->2->3

Program

Below is a program for the same

package main
import "fmt"
func main() {
first := initList()
first.AddFront(1)
first.AddFront(2)
first.AddFront(3)
first.AddFront(4)
first.Head.Traverse()
first.Reverse()
fmt.Println("")
first.Head.Traverse()
}
func initList() *SingleList {
return &SingleList{}
}
type ListNode struct {
Val int
Next *ListNode
}
func (l *ListNode) Traverse() {
for l != nil {
fmt.Println(l.Val)
l = l.Next
}
}
type SingleList struct {
Len int
Head *ListNode
}
func (s *SingleList) Reverse() {
curr := s.Head
var prev *ListNode
var next *ListNode
for curr != nil {
next = curr.Next
curr.Next = prev
prev = curr
curr = next
}
s.Head = prev
}
func (s *SingleList) AddFront(num int) {
ele := &ListNode{
Val: num,
}
if s.Head == nil {
s.Head = ele
} else {
ele.Next = s.Head
s.Head = ele
}
s.Len++
}

Output

4
3
2
1
1
2
3
4

Note: Check out our Golang Advanced Tutorial. The tutorials in this series are elaborative and we have tried to cover all concepts with examples. This tutorial is for those who are looking to gain expertise and a solid understanding of golang – Golang Advance Tutorial

Also if you are interested in understanding how all design patterns can be implemented in Golang. If yes, then this post is for you –All Design Patterns Golang