main.go

package main

import (
	"fmt"
	"os"
	"strconv"
)

func main() {
	in, _ := strconv.Atoi(os.Args[1])
	fmt.Println(Nearest([]int{3, -20, 1, -8, 7, 4, 11, -3}, in))
}

func Nearest(data []int, to int) int {
	if len(data) == 1 {
		return data[0]
	}

	current := data[0]
	nearest := Nearest(data[1:], to)
	if diff(current, to) < diff(nearest, to) {
		return current
	}

	return nearest

}

func diff(a, b int) int {
	d := a - b
	if d < 0 {
		return -d
	}
	return d
}