package main

import "fmt"

func getBool(i, j int) bool {
	if i <= j{
		return true
	}else {
		return false
	}
}

func checkBin(list []int, i int) bool {
	low := 0
	high := len(list) -1
	for ok := true;ok ;ok = getBool(low,high)  {
		mid:= (low+high)/2
		if list[mid] == i{
			return true
		}
		if list[mid] < i{
			low = mid+1
		}else {
			high = mid -1
		}
	}
	return false
}

func main() {
	fmt.Println(checkBin([]int{1, 2, 3, 4, 5}, 1)) // true
	fmt.Println(checkBin([]int{1, 2, 3, 4, 5}, -1)) //false
}