快速排序

public class QuickSort {

    static void sort(int a[],int start,int end) {
        
        int temp = a[start];
        int i = start;
        int j = end;
        
        while(i<j) {
            while(i<j&&a[j]>=temp) {
                j--;
            }
            if(i<j) {
                a[i]=a[j];
            }
            while(i<j&&a[i]<temp) {
                i++;
            }
            if(i<j) {
                a[j]=a[i];
            }
        }
        
        a[i] = temp;
        
        if(i-start>1)
            QuickSort.sort(a,start,i-1);
        if(end-j>1)
            QuickSort.sort(a,j+1,end);
    
        
    }
    
    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int a[]= {1,5,2,99,545,5,7};
        for(int i = 0;i<a.length;i++)
        System.out.print(a[i]+" ");
        System.out.println();
        sort(a,0,a.length-1);
        for(int i = 0;i<a.length;i++)
        System.out.print(a[i] + " ");
        System.out.println();

    }

}