fibonni

fib.go

package main

import "fmt"
import "os"
import "strconv"


func main() {
    if len(os.Args) < 2 {
        fmt.Println("no")
        return
    }
    arg := os.Args[1]
    
    i, err := strconv.Atoi(arg)

    if err != nil {
        return 
    }
        

    fmt.Printf("%d", fib(i))
}

func fib(n int) (int) {
    var a [20]int 
    a[0] = 0
    a[1] = 1

    for i := 2; i <= n; i++ {
       a[i] = a[i-1] + a[i-2]; 
    }

    return a[n]
}