C++实现归并排序算法

#include <iostream>

using namespace std;

//比较相邻序列
void Merge(int arr[],int temp[],int start,int mid,int end){
  int i = start,j = mid + 1,k = start;
  //将较小值放入申请序列
  while(i != mid+1 && j != end+1){
    if(arr[i] > arr[j])
      temp[k++] = arr[j++];
    else
      temp[k++] = arr[i++];
  }
 
 //将多余的数放到序列末尾
  while(i != mid+1)
    temp[k++] = arr[i++];

  while(j != end+1)
    temp[k++] = arr[j++];

 //更新序列
  for(i = start;i <= end;i++)
    arr[i] = temp[i];
}

void MergeSort(int arr[],int temp[],int start,int end){
  int mid;
  if(start < end){
   //避免堆栈溢出
    mid = start + (end - start) / 2;
    //递归调用
    MergeSort(arr,temp,start,mid);
    MergeSort(arr,temp,mid+1,end);
    Merge(arr,temp,start,mid,end);
  }
}

int main(){
  int a[8] = {50, 10, 20, 30, 70, 40, 80, 60};
  int i, b[8];
  MergeSort(a, b, 0, 7);
  for(i=0; i<8; i++)
    cout<<a[i]<<" ";

  return 0;
}