Page 72, Exercise 3: pmult()

void pmult(polynomial a [] , polynomial b [], polynomial c [], int na, int nb, int *nc)
{/*multiply two polynomials */
   int i, j;
   *nc = 0;
     for (i = 0; i < na; i++)
      for (j = 0; j < nb; j++) {
	      c[*nc].coef = a[i].coef * b[j].coef;
		  c[(*nc)++].expon = a[i].expon + b[j].expon;
	  }
	  /*put simplification here if you wish */
	}