public class HNT {

     public static void main(String[] args) {

         HNT a1 = new HNT();

         a1.lToR(10);    //给汉诺塔a1左边放10阶的层数，把左边的10阶移动至右边。

     }

     private boolean pHToM(int num,String a,String b,String c) {        //打印移动数据，从a移动到c.

         if (num == 1) {        //只移动一层的情况，return false表示，如果num == 1则不再继续打印num<1的情况

             System.out.printf("%s to %s\n",a,c);

             return false;

         }

         else if (num == 2) {    //只移动两层的情况,return false表示，如果num == 2则不再继续打印num<2的情况

             System.out.printf("%s to %s\n",a,b);

             System.out.printf("%s to %s\n",a,c);

             System.out.printf("%s to %s\n",b,c);

             return false;

         }

         else {        //

             return true;    //移动大于两层的情况，return true表示，如果num>2则继续循环到num<=2为止

         }

     }

     public void lToR(int num) {        //把num层的汉诺塔从左移动至右

         if(pHToM(num,"left","mid","right")) {

             lToM(num - 1);

             lToR(1);

             mToR(num - 1);

         }

     }

     public void lToM(int num) {        //把num层的汉诺塔从左移动至中

         if(pHToM(num,"left","right","mid")) {

             lToR(num - 1);

             lToM(1);

             rToM(num - 1);

         }

     }

     public void mToL(int num) {        //把num层的汉诺塔从中移动至左

         if(pHToM(num,"mid","right","left")) {

             mToR(num - 1);

             mToL(1);

             rToL(num - 1);

         }

     }

     public void mToR(int num) {        //把num层的汉诺塔从中移动至右

         if(pHToM(num,"mid","left","right")) {

             mToL(num - 1);

             mToR(1);

             lToR(num - 1);

         }

     }

     public void rToL(int num) {        //把num层的汉诺塔从右移动至左

         if(pHToM(num,"right","mid","left")) {

             rToM(num - 1);

             rToL(1);

             mToL(num - 1);

         }

     }

     public void rToM(int num) {        //把num层的汉诺塔从右移动至中

         if(pHToM(num,"right","left","mid")){

             rToL(num - 1);

             rToM(1);

             lToM(num - 1);

         }

     }

 }