Call:   a =  ReadPoly();
    

PolyPointer ReadPoly()
{/*read the polynomial into a chain */
  PolyPointer front, rear,temp;
  float coefficient;
  int exponent;
  front=rear=NULL;
  printf("Enter an exponent Less than 0 to quit: \n");
  printf("Coefficient, Exponent: ");
  scanf("%f,%d",&coefficient,&exponent);
  while (exponent >= 0) {
     temp = (PolyPointer)malloc(sizeof(struct PolyNode));
     temp->coef =  coefficient;
     temp->expon = exponent;
     temp->link = NULL;
     if (!front) front = temp;
     else rear->link = temp;
     rear = temp;
     printf("Coefficient, Exponent: ");
     scanf("%f,%d",&coefficient,&exponent);
     }
     return front;
}