package main

import (
    "testing"
)

type Node struct {
    Value int
    Next  *Node
}

func RReverse(node *Node) *Node {
    if node == nil {
        return node
    }
    if node.Next == nil {
        return node
    }
    next := node.Next
    node.Next = nil
    last := RReverse(next)
    next.Next = node
    return last
}

func IReverse(node *Node) *Node {
    var previous *Node
    for node != nil {
        next := node.Next
        node.Next = previous
        previous = node
        node = next
    }
    return previous
}

func build(size int) *Node {
    var next *Node
    for i := size; i > 0; i-- {
        next = &Node{i, next}
    }
    return next
}

const max = 10000

func BenchmarkRecursive(b *testing.B) {
    for i := 0; i < b.N; i++ {
        if last := RReverse(build(max)).Value; last != max {
            panic(last)
        }
    }
}

func BenchmarkIterative(b *testing.B) {
    for i := 0; i < b.N; i++ {
        if last := IReverse(build(max)).Value; last != max {
            panic(last)
        }
    }
}