尝试在Java中实现归并排序。我在脑海中反复检查了我的代码，觉得它应该是可以工作的，但显然我做错了些什么。以下是代码部分：
```java
    public static void mergeSort(int[] input, int start, int end) {
        if (end - start < 2)
            return;
        
        int mid = (start + end) / 2;
        mergeSort(input, start, mid);
        mergeSort(input, mid + 1, end);
        merge(input, start, mid, end);
    }
    public static void merge(int[] input, int start, int mid, int end) {
        if (input[mid - 1] <= input[mid])
            return;
         
        int i = start;
        int j = mid;
        int tempIndex = 0;
        int[] temp = new int[end - start]; //合并两个数组的大小
        
        /* 如果 i >= mid，意味着数组的左部分已经排序完成，
           反之如果 j >= end，那么右部分也是一样的。
           一旦发生这种情况，我们可以将剩余的元素直接复制到临时数组中。
        */
        while (i < mid && j < end) {
            temp[tempIndex++] = (input[i] <= input[j]) ? input[i++] : input[j++];
        }
        
        // 复制左部分中剩余的元素
        while (i < mid)
            temp[tempIndex++] = input[i++];
        
        // 复制右部分中剩余的元素
        while (j < end)
            temp[tempIndex++] = input[j++];
        
        // 将排序后的临时数组复制回原数组
        // 这是我认为可能出错的地方
        for (int k = 0; k < temp.length; k++) {
            input[start + k] = temp[k];    
        }
     }

<details>
<summary>英文:</summary>
Trying to implement merge sort in Java. I&#39;ve gone over my code a bunch in my head and I feel like it should be working, but obviously I&#39;m doing something wrong. Heres the code

public static void mergeSort(int[] input, int start, int end) {
if (end - start < 2)
return;
int mid = (start + end) / 2;
mergeSort(input, start, mid);
mergeSort(input, mid + 1, end);
merge(input, start, mid, end);
}
public static void merge(int[] input, int start, int mid, int end) {
if (input[mid - 1] <= input[mid])
return;
int i = start;
int j = mid;
int tempIndex = 0;
int[] temp = new int[end - start]; //combined size of both arrays being merged
/*if i is >= mid, then that means the left portion of the array is done being sorted
and vice versa if j >= end. Once this happens, we should be able to
just copy the remaining elements into the temp array 
*/
while (i < mid && j < end) {
temp[tempIndex++] = (input[i] <= input[j]) ? input[i++] : input[j++];
}
//Copying left over elements in left portion
while (i < mid)
temp[tempIndex++] = input[i++];
//Copying left over elements in right portion
while (j < end)
temp[tempIndex++] = input[j++];
//Copy the sorted temp array into the original array
//This is where I think I must be messing up
for (int k = 0; k < temp.length; k++) {
input[start + k] = temp[k];    
}
}

I think it must be that im not copying correctly the temp array with the sorted elements back into the original array, but I'm not sure. I wrote comments on my code explaining my logic. 
</details>
# 答案1
**得分**: 2
看一下以下的变更：
1. 计算中间值
&gt; int mid = start + (end - start) / 2;
2. 正确地分配指针 i 和 j。
&gt; int i = start;
&gt; int j = mid+1;
3. 正确的临时数组大小。
&gt; int [] temp = new int[end-start+1];
4. 修正了代码中的 while 循环条件。
class Solution{
public static void mergeSort(int[] input, int start, int end) 
{
if (end == start ) return;
int mid = start + (end - start) / 2;
mergeSort(input, start, mid);
mergeSort(input, mid+1, end);
merge(input, start, mid, end);
}
public static void merge(int[] input, int start, int mid, int end) {
// 下面这个指令是不必要的
// if(input[mid-1] &lt;= input[mid]) return;
int i = start;
int j = mid+1;
int tempIndex = 0;
int [] temp = new int[end-start+1]; // 被合并的两个数组的总大小
/* 如果 i &gt;= mid，则意味着数组的左部分已经排序完成，反之亦然，如果 j &gt;= end，则意味着数组的右部分已经排序完成。一旦发生这种情况，我们应该能够将剩余的元素直接复制到临时数组中 */
while(i &lt;= mid &amp;&amp; j &lt;= end){
temp[tempIndex++] = (input[i] &lt;= input[j]) ? input[i++] : input[j++];
}
// 复制左部分中剩余的元素
while(i &lt;= mid)
temp[tempIndex++] = input[i++];
// 复制右部分中剩余的元素
while(j &lt;= end)
temp[tempIndex++] = input[j++];
// 将排序好的临时数组复制到原始数组中
// 这是我认为我可能搞错的地方
for(int k = 0; k &lt; temp.length; k++){
input[start+k] = temp[k];    
}
}
public static void main(String[] args){
int[] input = {9,4,6,8,5,7,0,2};
mergeSort(input,0,7);
for(int i : input)
System.out.println(i);    
}
}
<details>
<summary>英文:</summary>
Take a look at the following changes:
1. Calculating mid
&gt; int mid = start + (end - start) / 2;
2. Assigning pointers i,j correctly.
&gt; int i = start;
&gt; int j = mid+1;
3. Correct size of temp array.
&gt; int [] temp = new int[end-start+1];
4. Corrected while loops condition in the code.
class Solution{
public static void mergeSort(int[] input, int start, int end) 
{
if (end == start ) return;
int mid = start + (end - start) / 2;
mergeSort(input, start, mid);
mergeSort(input, mid+1, end);
merge(input, start, mid, end);
}
public static void merge(int[] input, int start, int mid, int end) {
// No Need of the under mentioned instruction
// if(input[mid-1] &lt;= input[mid]) return;
int i = start;
int j = mid+1;
int tempIndex = 0;
int [] temp = new int[end-start+1]; //combined size of both arrays being merged
/*if i is &gt;= mid, then that means the left portion of the array is done being sorted and vice versa if j &gt;= end. Once this happens, we should be able to just copy the remaining elements into the temp array */
while(i &lt;= mid &amp;&amp; j &lt;= end){
temp[tempIndex++] = (input[i] &lt;= input[j]) ? input[i++] : input[j++];
}
//Copying left over elements in left portion
while(i &lt;= mid)
temp[tempIndex++] = input[i++];
//Copying left over elements in right portion
while(j &lt;= end)
temp[tempIndex++] = input[j++];
//Copy the sorted temp array into the original array
//This is where I think I must be messing up
for(int k = 0; k &lt; temp.length; k++){
input[start+k] = temp[k];    
}
}
public static void main(String[] args){
int[] input = {9,4,6,8,5,7,0,2};
mergeSort(input,0,7);
for(int i : input)
System.out.println(i);    
}
}
</details>