#include <stdio.h>
struct list {
  int pow,coef;
  struct list *next;
};
typedef struct list node;
typedef node *link;
void print_poly(link head) {
  link pt1;

  printf("the input polynomial ---> f(X)=");
  pt1=head;
  while (pt1 != NULL) {
    if (pt1->pow != 0) printf("%2dX%2d",pt1->coef,pt1->pow);
    else printf("%2d",pt1->coef);
    pt1=pt1->next; if (pt1 != NULL) printf("+");
  }
  printf("\n");
}

link create() {
  link head,pt1,pt2,pt3;
  int c,p,i;

  head=NULL; i=0;
  while (1) {
    printf("give me coefficient and power ?"); scanf("%d %d",&c,&p);
    if ((c == 0) && (p == 0)) break;
    if (i == 0) {
      i=1; head=pt2=(link)malloc(sizeof(node)); pt2->coef=c; pt2->pow=p;
      pt2->next=NULL;
    }
    else { /* 2th node after */
      if (p > head->pow) { /* insert head */
	pt2=(link)malloc(sizeof(node)); pt2->coef=c; pt2->pow=p;
	pt2->next=head; head=pt2;
      }
      else { /* insert middle, end */
	pt3=head;
	while (pt3->pow > p) {
	  pt1=pt3; pt3=pt3->next;
	}
	/* pt3->pow < = p */
	if (pt3->pow == p) pt3->coef+=c;
	else { /* < */
	  pt2=(link)malloc(sizeof(node)); pt2->coef=c; pt2->pow=p;
	  pt2->next=pt1->next; pt1->next=pt2;
	}
      }
    }
  }
  return head;
}

void main() {
  int c,p;
  link h1;

  printf("give me the polymonial -->"); h1=create(); print_poly(h1);
}