public static void quick(int[] arr, int begin, int end) {//结束所以不包含if (end - begin <&#61; 1) {return;}//分区&#xff0c;分三个部分&#xff0c;中间是键&#xff0c;左边是比键小&#xff0c;右面比键大//定位键索引最关键int key &#61; arr[begin];//总是取第一个元素为键值int keyIndex &#61; begin;//键索引值&#xff0c;用于动态保存比键值小的值for (int i &#61; begin &#43; 1; i