快速排序

package sdu.ocean;

public class quickSort {

	public static void main(String[] args) {

		int a[] = { 0, 10, 4, 1, 6, 4, 8, 9, 5, 23, 12, 65, 43 };//不用0位置
		new quickSort().quick(a, 1, 12);
		for(int i = 1 ; i < a.length; i++){
			System.out.print(a[i]+"  ");
		}

	}

	public int partition(int a[], int f, int r) {
		
		int point = f;
		int i = f + 1;
		int j = r;
		int p = a[point];
		while(true){
			while (i<13 && a[i] < p){   //判断下是否越界
				i++;
			}
			while (j>0 && a[j] > p){    //判断下是否越界
				j--;
			}

			if (j <= i) {
				break;
			} else {
				int x = a[j];
				a[j] = a[i];
				a[i] = x;
			}
		}
		
		a[point] = a[j];
		a[j] = p;
		
		return j;
		
	}

	public void quick(int a[] , int f, int r){
		if(f<r){
			int p = partition(a,f,r);
			quick(a,f,p-1);
			quick(a,p+1,r);
		}
	}
}