快速排序&易错点

</pre><pre name="code" class="cpp">

#include <iostream>
using namespace std;

int partition(int* arr, int p, int q){
	int pivot = arr[p];

	while (p < q) // while中统一使用p < q 而不是p <= q
	{
		while(pivot <= arr[q] && p < q)
			q--;
		arr[p] = arr[q];
		while(pivot >= arr[p] && p < q)
			p++;
		arr[q] = arr[p];
	}
	arr[p] = pivot;//记住把pivot归位
	return p;
}

void quick_sort(int* arr, int start, int end){
	if(start >= end) return; //递归出口
	int pos = partition(arr, start, end);
	quick_sort(arr, start, pos - 1);
	quick_sort(arr, pos + 1, end);
}


int main(){
	int arr[] = { 3, 5, 6 ,8, 2, 1, 9, 4, 0, 7};
	quick_sort(arr, 0, 9);
	for(int i = 0; i < 10; i++){
		cout << arr[i] << " ";
	}
	system("PAUSE");
}

别人的快排