习题9

9.1.1void swap(int *x,int *y)
     {
         int *ptemp;
         *ptemp=*x;
         *x=*y;
         *y=*ptemp;
     }

9.1.2void swap(int *x,*y)
     {
      int*ptemp;
     ptemp=x;
     x=y;
     y=ptemp;
     }

9.2