#include<stdio.h>
 #define C 14
 #define P 10
 #define R 6

 main ( ) {
     long long i = 74724183943651LL;//两个LL是什么意思？
     int d, j = 1, k = 9;
     double x = 0.0;

     while ( i > 0 ) {
         d = i % 10;//d=1吗？
         switch ( j ) //j=1, 为什么case后面是字母呢？
  {
         case C:
             printf("The company name is %d\n", k);
             break;
         case P:
             printf("The product number is %d\n", k);
             k = 0;
             break;
         case R:
             k = 0;
         }
         if ( j < 6 )
             x = 10.0 * x + (double) d;
         else
             k = 10 * k + d;
         i /= 10;
         j++;
    }
    printf("The price is $%.2lf\n", x / 100 );

}

可以运行，结果是：
The product number is 9381
The company name is 4274
The price is $156.34
就是看不懂为啥。

楼上的兄弟，你已经让俺佩服得五体投地了。