插入排序 选择排序 冒泡排序 快速排序

插入排序：

#include <iostream>
using namespace std;

void insertSort(int *a,int n)
{
	for(int i=0;i<n-1;++i)
	{
		int cur = a[i+1];
		int j=i;
		while (j>=0)
		{
			if (cur<a[j])
			{
				a[j+1] = a[j];
				--j;
			}
			else
				break;
		}
		a[j+1] = cur;
		
	}
}

int main()
{
	int a[] = {1,15,2,33,66,11,32,99};
	insertSort(a,8);
	for (int i=0;i<8;++i)
		cout<<a[i]<<" ";
}

冒泡排序：

#include <iostream>
using namespace std;

void bubbleSort(int *a,int n)
{
	for (int i=0;i<n-1;++i)
	{
		bool flag = true;
		for (int j=n-1;j>i;--j)
		{
			if (a[j]<a[j-1])
			{
				int temp = a[j-1];
				a[j-1] = a[j];
				a[j] = temp;
				flag = false;
			}
		}
		if (flag)
			break;
	}
}

int main()
{
	int a[] = {1,3,2,66,77,55,0,6,5,100};
	bubbleSort(a,10);
	for (int i=0;i<10;++i)
		cout<<a[i]<<" ";
}

选择排序：

#include <iostream>
using namespace std;

void selectSort(int *a,int n)
{
	for (int i=0;i<n-1;++i)
	{
		int lower = i;
		for (int j=i+1;j<n;++j)
		{
			if (a[j]<a[lower])
				lower = j;
		}
		int temp = a[i];
		a[i] = a[lower];
		a[lower] = temp;
	}
}

int main()
{
	int a[]={1,55,2,77,3,88,97,56,0,11};
	selectSort(a,10);
	for (int i=0;i<10;++i)
		cout<<a[i]<<" ";
}

快速排序，两种方法：

#include <iostream>
using namespace std;

void quickSort1(int *a,int left,int right)
{
	if (left<right)
	{
		int temp = a[left];
		int l = left,r = right;
		while (l<r)
		{
			while (a[r]>temp && l<r)
				--r;
			a[l] = a[r];
			while (a[l]<temp && l<r)
				++l;
			a[r] = a[l];
		}
		a[l] = temp;

		quickSort1(a,left,l-1);
		quickSort1(a,l+1,right);
	}
}

int partition(int *a,int left,int right,int target)
{
	while (left<right)
	{
		while ( left<right & a[++left]<target);
		while ( left<right && a[--right]>target);

		int temp = a[left];
		a[left] = a[right];
		a[right] = temp;
	}
	return left;
}

void quickSort2(int *a,int left,int right)
{
	if (left>=right)
		return;
	
	int pivotindex = (left+right)/2;
	int temp = a[right];
	a[right] = a[pivotindex];
	a[pivotindex] = temp;

	int p = partition(a,left-1,right,a[right]);
	
	temp = a[p];
	a[p] = a[right];
	a[right] = temp;

	quickSort2(a,left,p-1);
	quickSort2(a,p+1,right);
}

int main()

{
	int a[]={5,7,3,8,1,22,66,12,32,15};
	quickSort2(a,0,9);
	for (int i=0;i<10;++i)
		cout<<a[i]<<" ";
}