C++实现各种交换排序(冒泡，快速)

Posted 2021-05-23 Wecccccccc

冒泡排序:

代码如下:

#include <iostream>
using namespace std;

void BubbleSort(int *a, int len)
{//数组下标从0开始
	for (int i = 1;i<=len-1;i++)//共需要len-1趟
		for (int j = 1; j <= len - i; j++)//第i趟的比较次数是len-i次
			if (a[j - 1] > a[j])
			{
				int temp = a[j - 1];
				a[j - 1] = a[j];
				a[j] = temp;
			}
}

int main()
{
	int a[] = { 1231,34,532,5,4,124,214,12,3,14 };
	BubbleSort(a, 10);
	for (int i = 0; i < 10; i++) cout << a[i] << " ";
	cout << endl;
	return 0;
}

冒泡排序(优化):

代码如下:

#include <iostream>
using namespace std;

void BubbleSort(int *a, int len)
{//数组下标从0开始
	bool flag = true;
	for (int i = 1; i <= len - 1 && flag; i++)//共需要len-1趟
	{					
		flag = false;
		for (int j = 1; j <= len - i; j++)//第i趟的比较次数是len-i次
			if (a[j - 1] > a[j])
			{
				flag = true;
				int temp = a[j - 1];
				a[j - 1] = a[j];
				a[j] = temp;
			}
	}
}

int main()
{
	int a[] = { 1,3,54,554,4264,5234,68658,70000,88888,999999 };
	BubbleSort(a, 10);
	for (int i = 0; i < 10; i++) cout << a[i] << " ";
	cout << endl;
	return 0;
}

快速排序:

代码如下:

#include <iostream>
using namespace std;
int Partition(int *a, int low, int high);
void QSort(int *a, int low, int high)
{//数组下标从1开始
	if (low < high)
	{
		int pivotloc = Partition(a, low, high);

		QSort(a, low, pivotloc - 1);
		QSort(a, pivotloc + 1, high);
	}
}

int Partition(int *a, int low, int high)
{
	a[0] = a[low];
	int pivotkey = a[low];
	while (low < high)
	{
		while (low < high && a[high] >= pivotkey) --high;
		a[low] = a[high];
		while (low < high && a[low] <= pivotkey) ++low;
		a[high] = a[low];
	}
	a[low] = a[0];
	return low;
}


int main()
{
	int a[] = { 0,123,14124,4,214,23,4,324,24,124,24 };
	QSort(a, 1, 10);
	for (int i = 1; i <= 10; i++) cout << a[i] << " ";
	cout << endl;
	return 0;
}