我想问问，这归并排序为什么排不了啊😭

Question

排序完的数组出现0，-1，和原来的数组不同，为什么会这样呢？

Answer 1

#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include <malloc.h>
#include <windows.h>
#include <memory.h>
//归并排序：
/*
arr:指定数组
left:判定左边界
right:判断右边界
mid:判断中点
*/
void Merge(int* arr, int left, int right, int mid)
{
    int *p = (int*)malloc((right - left + 1) * sizeof(int));
    int *temp = p;
    memset(p, 0, (right - left + 1) * sizeof(int));
    int L = left;
    int R = mid + 1;
    while (L <= mid && R <= right)
    {
        *p++ = arr[L] < arr[R] ? arr[L++] : arr[R++];
    }
    while (L <= mid)
    {
        *p++ = arr[L++];
    }
    while (R <= right)
    {
        *p++ = arr[R++];
    }
 
    memcpy(arr + left, temp, (right - left + 1) * sizeof(int));
 
    free(temp);
    temp = NULL;
}
 
void MergeSort(int* arr, int left, int right)
{
    if (left == right)
        return;
    int mid = left + ((right - left)>>1);
 
    MergeSort(arr, left, mid);            //左半边
    MergeSort(arr, mid + 1, right);        //右半边
    Merge(arr, left, right, mid);        //排序
}
 
int main()
{
    int arr[10] = { 9,8,3,5,2,1,6,4,7,10};
    MergeSort(arr, 0, sizeof(arr)/ sizeof(arr[0]) - 1);
 
    for (int i = 0; i < sizeof(arr) / sizeof(arr[0]); i++)
    {
        printf("%d ", arr[i]);
    }
 
    system("pause");
    return 0;
}