C語言歸併排序

廢話很少說直接上代碼

#include <stdio.h>
#include <stdlib.h>

/*
Description: 歸併排序
Author: QinGQ
Datetime: 2021年3月8日20點03分 
*/

int Length;                                     //待排序數組長度
int *A;                                         //待排序數組
int *B;                                         //輔助數組B
void MergeSort(int *A, int low, int high);      //歸併排序
void Merge(int *A, int low, int mid, int high); //合併子數組
void printnums(int *A);                         //打印數組

int main()
{
  puts("請輸入待排序數組的長度:");
  scanf("%d", &Length);
  A = (int *)malloc(sizeof(int) * Length);
  B = (int *)malloc(sizeof(int) * Length);
  puts("請輸入待排序數組:");
  for (int i = 0; i < Length; i++)
  {
    scanf("%d", &A[i]);
  }
  MergeSort(A, 0, Length - 1);
  printnums(A);
  system("pause");
  return 0;
}

void Merge(int *A, int low, int mid, int high)
{
  //將A中的元素複製到輔助數組B中
  for (int i = low; i <= high; i++)
  {
    B[i] = A[i];
  }
  int i, j, k;
  //依次挑選兩個子數組的較小的元素放入原數組，知道其中一個被挑完
  for (i = low, j = mid + 1, k = i; i <= mid && j <= high; k++)
  {
    if (B[i] <= B[j])
    {
      A[k] = B[i++];
    }
    else
    {
      A[k] = B[j++];
    }
  }
  //將剩餘的那個數組所有放回原數組
  while (i <= mid)
  {
    A[k++] = B[i++];
  }
  while (j <= high)
  {
    A[k++] = B[j++];
  }
}

void MergeSort(int *A, int low, int high)
{
  if (low < high)
  {
    int mid = (low + high) / 2;  //從中間劃分兩個子數組
    MergeSort(A, low, mid);      //遞歸排序左邊子數組
    MergeSort(A, mid + 1, high); //遞歸排序右邊子數組
    Merge(A, low, mid, high);    //歸併
  }
}

void printnums(int *A)
{
  for (int i = 0; i < Length; i++)
  {
    printf("%d ", A[i]);
  }
  puts("");
}

若有錯誤歡迎指正！