Golang优雅写法

package main
import "fmt"
func BinarySearch(arr []int, target int) int {
    l := 0
    r := len(arr) - 1
    for l < r {
        mid := (l + r) >> 1
        if arr[mid] >= target {
            r = mid
        } else {
            l = mid + 1
        }
    }
    return l
}

func BinarySearch1(arr []int, target int) int {
    l := 0
    r := len(arr) - 1
    for l < r {
        mid := (l + r + 1) >> 1
        if arr[mid] <= target {
            l = mid
        } else {
            r = mid - 1
        }
    }
    return l
}

func DoBlackInput(n int) []int {
    arr := make([]int, n)
    for i := 0; i < n; i++ {
        fmt.Scan(&arr[i])
    }
    return arr
}


func main() {
    var n int
    var q int
    fmt.Scan(&n, &q)
    arr := DoBlackInput(n)
    for i:=0; i<q;i++ {
        var target int
        fmt.Scan(&target)
        x := BinarySearch(arr, target)
        if arr[x] != target {
            fmt.Println("-1 -1")
            continue
        }
        y := BinarySearch1(arr, target)
        fmt.Printf("%d %d\n", x, y)
    }
}