问题

以下是您要求的翻译好的内容：

import java.util.*;

public class Binarysearch2 {

    static void bubblesort(int array[]) {
        int i, j, temp;
        for (i = 0; i < array.length - 1; i++) {
            for (j = 0; j < array.length - 1 - i; j++) {
                if (array[j + 1] > array[j]) {
                    temp = array[j];
                    array[j] = array[j + 1];
                    array[j + 1] = temp;
                }
            }
        }
    }

    static int search(int array[], int target) {
        int upper = array.length - 1;
        int lower = 0;

        while (lower <= upper) {
            int middle = (lower + upper) / 2;
            if (array[middle] == target) {
                return middle;
            } else if (array[middle] < target) {
                lower = middle + 1;
            } else {
                upper = middle - 1;
            }
        }
        return -1;
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("输入数组长度：");
        int length = scanner.nextInt();
        Random random = new Random();
        int i;
        int array[] = new int[length];
        for (i = 0; i < length; i++) {
            array[i] = (1 + random.nextInt(6));
            System.out.print(array[i] + " ");
        }
        System.out.println();
        System.out.println("输入目标数字：");
        int target, result;
        target = scanner.nextInt();
        bubblesort(array);
        result = Binarysearch2.search(array, target);

        if (result == -1) {
            System.out.println("目标不在数组中。");
        } else {
            System.out.println(target + " 在数组中，位于索引 " + result + " 处。");
        }
    }
}

如果您认为二分查找中有问题，请检查 if (orta < aranan) 这一行，可能应该是 if (dizi[orta] < aranan)。

import java.util.*;
public class Binarysearch2 {
static void bubblesort(int dizi[]){  // bubblesort //
int o,p,temp;
for(o=0;o<dizi.length-1;o++)
{
for(p=0;p<dizi.length-1-o;p++)
{
if(dizi
>dizi
){
temp=dizi
;
dizi
=dizi
;
dizi
=temp;
}
}
}
}
static int search(int dizi[],int aranan) // binary search//
{
int ust=dizi.length-1;
int alt=0;
while(alt<=ust)
{
int orta=(alt+ust)/2;
if(dizi[orta]==aranan){
return orta;
}
else if (orta<aranan)
{
alt=orta+1;
}
else
ust=orta-1;
}
return -1;
}
public static void main(String[]args) //main//
{
Scanner tara=new Scanner(System.in);
System.out.println("Enter array lenght");
int x=tara.nextInt();
Random rnd= new Random();
int i;
int a[]=new int[x];
for(i=0;i<x;i++)
{
a[i]=(1+rnd.nextInt(6));
System.out.print(a[i]+" ");
}
System.out.println();
System.out.println("Enter targeted number :");
int k,z;
k=tara.nextInt();
bubblesort(a);
z=Binarysearch2.search(a,k);
if(z==-1)
{System.out.println("Target is not in array.");}
else 
System.out.println(k+" in array "+z +" . at this index.");
}}

答案1

得分: 2

这里有一个问题：

if (orta<aranan)
{
    alt=orta+1;
}

与其将值（dizi[orta]）与目标（aranan）进行比较，你实际上比较的是索引。只需将条件替换为 if (dizi[orta]<aranan)

此外，正如安纳托利在他的答案中正确指出的，你的排序方向是错误的。你的冒泡排序在较小的元素在较大的元素之前时交换元素（if(dizi

>dizi

)。这意味着你是在降序中进行排序。另一方面，你的搜索假设数组是按升序排序的。

if (orta<aranan)
{
alt=orta+1;
}

答案2

得分: 1

Good day,
It would be really helpful if you'll be using English to name variables. Binary search makes an important assumption, that the array where you are seeking an element has been sorted. So, if you were to add sorting into the search method as follows, your code will work:

    static int search(int array[], int target) {
        int high = array.length - 1;
        int low = 0;

        Arrays.sort(array); // ADDED ELEMENT

        while (low <= high) {
            int mid = (low + high) / 2;
            if (array[mid] == target) {
                return mid;
            } else if (array[mid] < target) {
                low = mid + 1;
            } else {
                high = mid - 1;
            }
        }
        return -1;
    }

    static int search(int dizi[], int aranan) {
int ust = dizi.length - 1;
int alt = 0;
Arrays.sort(dizi); // ADDED ELEMENT
while (alt <= ust) {
int orta = (alt + ust) / 2;
if (dizi[orta] == aranan) {
return orta;
} else if (orta < aranan) {
alt = orta + 1;
} else
ust = orta - 1;
}
return -1;
}

答案3

得分: 1

1. 在 bubblesort 中，将 dizi

   > dizi

   更改为 dizi

   < dizi

   。

2. 在 search 中，将 else if (orta < aranan) 更改为 else if (dizi[orta] < aranan)。