使用二分查找法，查找一个有序的int[]中的某个数，并返回下标位置，如果不存在返回-1

public class Test2 {
     static int Ef(int[] arr,int ed){
         int left = 0;
         int right = arr.length-1;
         while(left <= right){
             int tmp = (left+right)/2;
             if(arr[tmp] > ed){
                 right = tmp-1;
             }else if(arr[tmp] < ed){
                 left = tmp + 1;
             }else{
                 return tmp;
             }
         }
         return -1;
     }
    public static void main(String[] args) {
        int[] arr = {1,2,3,4,8,10,59};
        int ed = 59;   //这是想要找下标的数字
        int back = Ef(arr, ed);
        if(back==-1){
            System.out.println("数组中不存在该数");
        }else{
            System.out.println(ed+"的下标："+back);
        }

    }
}