ch2_7.c

数据结构的一些小算法

#include <alloc.h>
#include <stdio.h>
typedef struct node
{  int coef,exp;
   struct node *next;
}JD;

void  add_poly(JD *pa,JD *pb)
{  JD *p,*q,*u,*pre;
   int x;
   p=pa->next;
   q=pb->next;
   pre=pa;
   while((p!=NULL) && (q!=NULL))
   {   if(p->exp<q->exp)
       {   pre=p;  p=p->next;}
       else if(p->exp==q->exp)
       {  x=p->coef+q->coef;
	  if(x!=0){ p->coef=x;  pre=p;}
	  else    { pre->next=p->next;  free(p);}
	  p=pre->next;
	  u=q;
	  q=q->next;
	  free(u);
       }
       else
       {    u=q->next;q->next=p;pre->next=q;
	    pre=q;  q=u;
       }
    }
    if(q!=NULL)
	pre->next=q;
    free(pb);
}
JD* dlbjl(int a[],int n)
{
	JD *s,*h;
	int i;
	h=(JD*)malloc(sizeof(JD));
	h->coef=h->exp=-1;
	h->next=NULL;
	for(i=n;i>0;i--)
	{s=(JD*)malloc(sizeof(JD));
	 s->coef=a[2*i-2];
	 s->exp=a[2*i-1];
	 s->next=h->next;
	 h->next=s;
	}
	return (h);
}
void dlbxs(JD *h)
{   JD *p;
    p=h->next;
    while(p!=NULL)
    {  printf("%d,%d\t",p->coef,p->exp);
       p=p->next;
    }
    printf("\n");
}


void main()
{  static int a[]={7,0,3,1,9,8,5,17};
   static int b[]={8,1,22,7,-9,8};
   JD *heada,*headb;
   int na=4,nb=3;
   heada=dlbjl(a,na);
   dlbxs(heada);
   headb=dlbjl(b,nb);
   dlbxs(headb);
   add_poly(heada,headb);
   dlbxs(heada);
}