c++快速排序

1、基于partition函数的快速排序

<span style="font-size:18px;">int partition(int *data, int start, int end){
	if(data == NULL || start > end){
		return -1;
	}
	int index = data[start];
	int i = start,j = end;
	while(i < j){
		while(i<j && data[j] >= index)
			j--;
		if(i<j)
			data[i++] = data[j];
		while(i<j && data[i] < index)
			i++;
		if(i<j)
			data[j--] = data[i];
	}
	data[i] = index;
	return j;
}
void quickSort(int *data,int start,int end){
	if(data == NULL)
		return ;
	if(start < end){
		int p = partition(data,start,end);
		quickSort(data,start,p-1);
		quickSort(data, p+1, end);
	}
}


int main (int argc, char* argv[])
{
	int data[] = {6,2,4,3,5,1,7,6,8,9};
	int length = sizeof(data)/sizeof(int);
	quickSort(data,0,length -1);
	for(int i = 0; i<length;i++)
		cout<<data[i]<<' ';
	cout<<endl;

	system("pause");
    return 0;
}</span>

2、直接的快速排序

<span style="font-size:18px;">void quickSort(int *data,int start,int end){
	if(data == NULL || start > end){
		return ;
	}
	int index = data[start];
	int i = start,j = end;
	while(i < j){
		while(i<j && data[j] >= index)
			j--;
		if(i<j)
			data[i++] = data[j];
		while(i<j && data[i] < index)
			i++;
		if(i<j)
			data[j--] = data[i];
	}
	data[i] = index;
	quickSort(data,start,i-1);
	quickSort(data, i+1, end);
}</span>