快速排序----区间分割法

#include<stdio.h>
int Sort(int arr[],int nLow,int nHigh)
{
	int temp;
	temp = arr[nLow];

	while(nLow < nHigh)
	{
		//从后向前找比标准值小的
		while(nHigh > nLow)
		{
			//找到了
			if(arr[nHigh] < temp)
			{
				//放到前面的坑
				arr[nLow] = arr[nHigh];
				nLow++;
				break;
			}
			nHigh--;
		}

		//从前向后找比标准值大的
		while(nLow < nHigh)
		{
			if(arr[nLow] > temp)
			{
				arr[nHigh] = arr[nLow];
				nHigh--;
				break;
			}
			nLow++;
		}
	}
	//标准值放入
	arr[nLow] = temp;
	return nLow;
}
int Sort2(int arr[],int nLow,int nHigh)
{
	int nSmall = nLow-1;

	for(nLow;nLow < nHigh;nLow++)
	{
		//找小的
		if(arr[nLow] < arr[nHigh])
		{
			//小区间扩张
			if(++nSmall != nLow)
			{
				arr[nLow] = arr[nLow]^arr[nSmall];
				arr[nSmall] = arr[nLow]^arr[nSmall];
				arr[nLow] = arr[nLow]^arr[nSmall];
			}
		}
	}

	//标准值放入
	if(++nSmall != nHigh)
	{
		arr[nSmall] = arr[nSmall]^arr[nHigh];
		arr[nHigh] = arr[nSmall]^arr[nHigh];
		arr[nSmall] = arr[nSmall]^arr[nHigh];
	}

	return nSmall;
}

void QuickSort(int arr[],int nLow,int nHigh)
{
	if(arr == NULL || nLow >= nHigh )return;

	//1.标准值
	int nStandard;
	nStandard = Sort2(arr,nLow,nHigh);

	//2.分割
	QuickSort(arr,nLow,nStandard-1);
	QuickSort(arr,nStandard+1,nHigh);
}

void Print(int arr[],int nLength)
{
	if(arr == NULL || nLength <= 0)return;

	int i;
	for(i = 0;i<nLength;i++)
	{
		printf("%d ",arr[i]);
	}
	printf("\n");
}
int main()
{
	int arr[] = {10,2,8,9,1,64,3,8,91};
	QuickSort(arr,0,sizeof(arr)/sizeof(arr[0])-1);
	Print(arr,sizeof(arr)/sizeof(arr[0]));
	return 0;
}