二分查找（Java）

題目：
編寫程序，完成如下功能:
(1)輸入5個整數到數組中;
(2)使用冒泡法對5個數按從小到大排序，輸出排序後的數組;
(3)輸入一個整數X，在數組中用二分法查找X，找到輸出X在數組中的下標，找不到輸出-1;

Java實現：

package com.company;
import java.util.Scanner;

class BinarySearch{
    public int BSearch(int []arr , int search){
        //冒泡排序
        int count = 0;
        while(count < arr.length){
            for(int i = 0 ; i < arr.length - 1 - count ; i ++){
                int temp = 0;
                if(arr[i] > arr[i+1]){
                    temp = arr[i];
                    arr[i] = arr[i+1];
                    arr[i+1] = temp;
                }
            }
            count ++;
        }

        //打印排序完的數組
        System.out.print("排序後的數組爲：");
        for(int i = 0 ; i < arr.length ; i ++){
            System.out.print(arr[i] + " ");
            if(i == arr.length - 1){
                System.out.println();
            }
        }

        //二分查找
        int top = 0;
        int rear = arr.length - 1;
        int mid = (top+rear)/2;

        if(search > arr[arr.length-1] || search < arr[0]){
            return -1;
        }

        while(top <= rear){
            mid = (top + rear) / 2;
            if(arr[mid] > search){
                rear = mid - 1;
            }else if(arr[mid] < search){
                top = mid + 1;
            }else{
                return mid;
            }
        }
        return -1;
    }
}

public class Test4 {
    public static void main(String[] args) {
        int []array = new int[5];
        //數組賦值
        System.out.println("請輸入5個整數:");
        Scanner input = new Scanner(System.in);
        for(int i = 0 ; i < 5 ; i ++){
            array[i] = input.nextInt();
        }

        BinarySearch bs = new BinarySearch();
        System.out.println("請輸入要查找的數字:");
        int search = input.nextInt();
        System.out.println("你要查找的數字的下標是："+bs.BSearch(array,search));
    }
}