C++实现各种选择排序(简单选择排序，堆排序)

Posted 2021-05-23 Wecccccccc

简单选择排序:

代码如下:

#include <iostream>
using namespace std;

void SelectSort(int *a, int len)
{//数组下标从0开始
	for (int i = 0; i < len; i++)
	{
		int k = i;
		for (int j = i + 1; j < len; j++)
			if (a[j] < a[k]) k = j;
		if (k != i)
		{
			int temp = a[i];
			a[i] = a[k];
			a[k] = temp;
		}
	}
}

int main()
{
	int a[] = { 21,3,24,24,23,42,4,235,27878,46 };
	SelectSort(a, 10);
	for (int i = 0; i < 10; i++) cout << a[i] << " ";
	cout << endl;
	return 0;
}

堆排序:

代码如下:

#include <iostream>
using namespace std;

void HeapAdjust(int *a, int s, int m)
{
	int rc = a[s];
	for (int i = 2 * s; i <= m; i *= 2)
	{
		if (i < m && a[i] < a[i + 1]) i++;
		if (rc > a[i]) break;
		a[s] = a[i];
		s = i;
	}
	a[s] = rc;
}

void CreatHeap(int *a, int n)
{
	for (int i = n / 2; i > 0; i--) HeapAdjust(a, i, n);
}

void HeapSort(int *a, int n)
{//数组下标从1开始
	CreatHeap(a, n);
	for (int i = n; i > 1; i--)
	{
		int temp = a[1];
		a[1] = a[i];
		a[i] = temp;
		HeapAdjust(a, 1, i - 1);
	}
}

int main()
{
	int a[] = { 0,1314,23,5,35,234,2,4,24,124,214 };
	HeapSort(a, 10);
	for (int i = 1; i <= 10; i++) cout << a[i] << " ";
	cout << endl;
	return 0;
}