Java快速排序

    
    private void quickSort(int[] arr, int start, int end){
        if(start < end){
            int i = start;
            int j = end;
            int standard = arr[start];
            
            while(i < j) {
                while(arr[j] >= standard && i < j) j--;
                while(arr[i] <= standard && i < j) i++;
                if(i < j){
                    int temp = arr[i];
                    arr[i] = arr[j];
                    arr[j] = temp;
                }
            }
            
            arr[start] = arr[i];
            arr[i] = standard;
            quickSort(arr, start, j - 1);
            quickSort(arr, j + 1, end);
        }
    }