Calculate the fibonacci number in three different ways

fibonacci.go

package main

import (
	"math/rand"
	"time"
)

//go:noinline
func fibonacciRecursive(n uint32) uint32 {
	if n < 2 {
		return n
	}
	return fibonacciRecursive(n-1) + fibonacciRecursive(n-2)
}

//go:noinline
func fibonacciCache(n uint32, cache map[uint32]uint32) uint32 {
	var i uint32
	for i = 2; i <= n; i++ {
		tmp := cache[i-1] + cache[i-2]
		cache[i] = tmp
	}
	return cache[n]
}

//go:noinline
func fibonacciLoop(n uint32) uint32 {
	var a uint32 = 0
	var b uint32 = 1
	for i := 0; i < int(n); i++ {
		a, b = b, a+b
	}
	return a
}

func init() {
	rand.Seed(time.Now().Unix())
}

func main() {
	for {
		num := rand.Uint32() % 32
		println(fibonacciRecursive(num))
		cache := make(map[uint32]uint32)
		cache[0] = 0
		cache[1] = 1
		println(fibonacciCache(num, cache))
		println(fibonacciLoop(num))
		time.Sleep(3 * time.Second)
	}
}