package main

import (
	"fmt"
)

func binSearch(t int, a []int) bool {
	if len(a) < 2 {
		return a[0] == t
	}
	mid := len(a) / 2
	switch {
	case t == a[mid]:
		return true
	case t < a[mid]:
		return binSearch(t, a[:mid])
	default:
		return binSearch(t, a[mid:])
	}
}

func main() {
	arr := []int{1,2,3,4,5,6,7,8,9,10}
	target := 4
	target2 := 11
	if binSearch(target, arr) {
		fmt.Println("pass")
	}
	if binSearch(target2, arr) {
		fmt.Println("fail")
	}
}