结构体排序

postgres中，需要修改一个sort方法，把源码中的快速排序改成能够加速的版本，把结构体中的key值搞出来，并且记录下标，把原来的sorttuple数组拷贝，然后按照排序过后的下标进行重新拷贝。

// qsort 的魔派、.cpp : 此文件包含 "main" 函数。程序执行将在此处开始并结束。
//

#include "pch.h"
#include <iostream>
using namespace std;
#define Datum unsigned __int64

typedef struct SortTuple 
{
	Datum datum1;
	char val;
}SortTuple;



static void quicksort(Datum *tuple_keys, int *indexs, size_t low, size_t high)//快速排序  kpu核函数
{
	if (low < high) 
	{
		size_t i = low, j = high;
		Datum privos = tuple_keys[low];//基准值
		int index = indexs[low];//基准值
		while (i < j) 
		{
			while (i<j&&tuple_keys[j]>=privos) j--;
			if (i < j) 
			{
				tuple_keys[i] = tuple_keys[j];
				indexs[i] = indexs[j];
			}
			while (i<j&&tuple_keys[i]<privos) i++;
			if (i < j) 
			{
				tuple_keys[j] = tuple_keys[i];
				indexs[j] = indexs[i];
			}
			
		}
		tuple_keys[i] = privos;
		indexs[i] = index;
		quicksort(tuple_keys, indexs,low,i);
		quicksort(tuple_keys, indexs, i+1, high);
		
	}
}

static void Dblib_qsort(SortTuple *a, size_t n)
{
	Datum *tuple_keys = (Datum *)malloc(n * sizeof(Datum));//保存sorttuple索引的数组
	int *indexs = (int*)malloc(n * sizeof(int));
	SortTuple *pm = a;
	for (size_t i = 0; i < n; i++)
	{
		tuple_keys[i] = pm->datum1;
		indexs[i] = i;
		pm++;
	}
	quicksort(tuple_keys, indexs, 0, n - 1);
	/*
	for (size_t i = 0; i < n; i++) 
	{
		cout<< tuple_keys [i]<<" ";
	}cout << endl;
	*/
	
	SortTuple *temp= (SortTuple*)malloc(n*sizeof(SortTuple));//拷贝暂存
	memcpy(temp,a, n * sizeof(SortTuple));//拷贝之后重新赋值
	for (size_t i = 0; i < n; i++) 
	{
		memcpy(&a[i],&temp[indexs[i]],sizeof(SortTuple));
	}
	
	
	free(temp);
	temp = NULL;
}


void init(SortTuple **a, size_t *n)
{
	cout<<"please input num of sorttuple"<<endl;
	int t;
	cin >> t;
	*n = t;
	*a = (SortTuple*)malloc((*n)*sizeof(SortTuple));
	//cout<<*n<<endl;
	for (size_t i = 0; i < (*n); i++)
	{
		Datum d; char c;
		cout << "please input datum1 of sorttuple:";
		cin >> d;
		cout << "please input value of sorttuple:";
		cin >> c;
		(*a)[i].datum1 = d; (*a)[i].val = c;//*a是指针
		cout << (*a)[i].val <<endl;
	}
}
void print(SortTuple *a, size_t n)
{
	cout<<"print value of sorttuple"<<endl;
	for (size_t i=0;i<n;i++)
	{
		cout<<a[i].datum1<<" "<<a[i].val<<endl;
	}cout << endl;
}
int main()
{
	SortTuple *a;
	size_t n=0;
	init(&a,&n);
	
	Dblib_qsort(a, n);

	print(a, n);
    std::cout << "Hello World!\n"; 
	//return 0;
}

// 运行程序: Ctrl + F5 或调试 >“开始执行(不调试)”菜单
// 调试程序: F5 或调试 >“开始调试”菜单

// 入门提示: 
//   1. 使用解决方案资源管理器窗口添加/管理文件
//   2. 使用团队资源管理器窗口连接到源代码管理
//   3. 使用输出窗口查看生成输出和其他消息
//   4. 使用错误列表窗口查看错误
//   5. 转到“项目”>“添加新项”以创建新的代码文件，或转到“项目”>“添加现有项”以将现有代码文件添加到项目
//   6. 将来，若要再次打开此项目，请转到“文件”>“打开”>“项目”并选择 .sln 文件

please input num of sorttuple
5
please input datum1 of sorttuple:7
please input value of sorttuple:c
c
please input datum1 of sorttuple:3
please input value of sorttuple:s
s
please input datum1 of sorttuple:3
please input value of sorttuple:n
n
please input datum1 of sorttuple:7
please input value of sorttuple:a
a
please input datum1 of sorttuple:0
please input value of sorttuple:m
m
print value of sorttuple
0 m
3 s
3 n
7 c
7 a

Hello World!