power.h

   1 struct power {
   2     int      n;
   3     Vector  *powers;
   4
   5     power(Value v, int max) {
   6         powers = Vector_Alloc(max+1);
   7         assert(powers);
   8         value_set_si(powers->p[0], 1);
   9         if (max >= 1)
  10             value_assign(powers->p[1], v);
  11         n = 2;
  12     }
  13     ~power() {
  14         Vector_Free(powers);
  15     }
  16     Value *operator[](int exp) {
  17         assert(exp >= 0);
  18         assert(exp < powers->Size);
  19         for (; n <= exp; ++n)
  20             value_multiply(powers->p[n], powers->p[n-1], powers->p[1]);
  21         return &powers->p[exp];
  22     }
  23 };