快速排序QuickSort

#include <iostream>
#include <exception>
#include <random>
#include <ctime>

using namespace std;

int RandomInRange(int start, int end)
{
	if (start < 0 || end < 0)
		throw new exception("无效的参数");

	srand((unsigned)time(NULL));
	if (start == end)
		return start;
	else if (start < end)
		return rand() % (end - start + 1) + start;
	else
		return rand() % (start - end + 1) + end;
}

int Partition(int data[], int length, int start, int end)
{
	if (data == nullptr || length <= 0 || start < 0 || end >= length)
		throw new exception("无效的参数");
	
	int index = RandomInRange(start, end);//随机生成一个标杆
	swap(data[index], data[end]);//把标杆放在最后一位，方便遍历
	int small = start - 1;
	for (index = start; index < end; ++index)
	{
		if (data[index] < data[end])
		{
			small++;
			if (small != index)//说明此时small和index之间有大于data[end]的元素
				swap(data[index], data[small]);
		}
	}
	small++;//此时small左边全是比data[end]小的元素，small指向了第一个比data[end]大的元素
	swap(data[end], data[small]);
	return small;
}
void QuickSort(int data[], int length, int start, int end)
{
	if (start == end)
		return;
	int index = Partition(data, length, start, end);

	if (index > start)
		QuickSort(data, length, start, index - 1);
	if (index < end)
		QuickSort(data, length, index + 1, end);
}

/*******************************测试代码****************************/

int* randomData(int n)//生成一个大小为n的随机数组
{
	int* data=(int*)malloc(n*sizeof(int));
	srand((unsigned)time(NULL));
	for (int i = 0; i < n; ++i)
	{
		data[i] = rand() % 100;
	}
	return data;
}

void ifPassed(int *data,int n)
{
	for (int i = 0; i < n - 1; ++i)
	{
		if (data[i] > data[i + 1])
		{
			cout << "失败" << endl;
			return;
		}
	}
	cout << "通过" << endl;
}

void test()
{
	int *data1=randomData(10);
	int *data2 = randomData(10);
	int *data3 = randomData(10);

	cout << "未排序的数据data1:" << endl;
	for (int i = 0; i < 10; ++i)
		cout << data1[i] << " ";
	cout << endl;
	QuickSort(data1, 10, 0, 9);
	cout << "排序完的数据data1：" << endl;
	for (int i = 0; i < 10; ++i)
		cout << data1[i] << " ";
	cout << endl;
	ifPassed(data1, 10);

	cout << "未排序的数据data2:" << endl;
	for (int i = 0; i < 10; ++i)
		cout << data2[i] << " ";
	cout << endl;
	QuickSort(data2, 10, 0, 9);
	cout << "排序完的数据data2：" << endl;
	for (int i = 0; i < 10; ++i)
		cout << data2[i] << " ";
	cout << endl;
	ifPassed(data2, 10);

	cout << "未排序的数据data3:" << endl;
	for (int i = 0; i < 10; ++i)
		cout << data3[i] << " ";
	cout << endl;
	QuickSort(data3, 10, 0, 9);
	cout << "排序完的数据data3：" << endl;
	for (int i = 0; i < 10; ++i)
		cout << data3[i] << " ";
	cout << endl;
	ifPassed(data3, 10);
}

int main()
{
	test();
	system("pause");
}