memoization attempt

package main

import (
	"fmt"
	"time"
)

func main() {
	var n int

	fmt.Print("Enter Number: ")
	fmt.Scanln(&n)

	fmt.Print("\nLoading....\n\n")

	start := time.Now()
	fmt.Println("Bottom Up: ", fib(n))
	fmt.Print(time.Since(start), "\n\n")

	start = time.Now()
	fmt.Println("Memoization: ", fibMemo(n))
	fmt.Print(time.Since(start), "\n\n")

	start = time.Now()
	fmt.Println("Recursion: ", fibRecur(n))
	fmt.Println(time.Since(start))

	fmt.Println()
}

func fibRecur(n int) int {
	var result int

	if n == 1 || n == 2 {
		result = 1
	} else {
		result = fibRecur(n-1) + fibRecur(n-2)
	}

	return result
}

func fibMemo(n int) int {
	var result int
	var memo []int

	if n <= len(memo) {
		if n == memo[n] {
			return memo[n]
		}
	}

	if n == 1 || n == 2 {
		result = 1
	} else {
		result = fibMemo(n-1) + fibMemo(n-2)
		memo = append(memo, result)
	}

	return result
}

func fib(n int) int {
	if n == 1 || n == 2 {
		return 1
	}

	var bottomUp []int
	bottomUp = append(bottomUp, 0)
	bottomUp = append(bottomUp, 1)
	bottomUp = append(bottomUp, 1)

	for i := 3; i <= n; i++ {
		bottomUp = append(bottomUp, bottomUp[i-1]+bottomUp[i-2])
	}

	return bottomUp[n]
}