/*这个程序是为了首先利用循环链表储存一个一元多项式，并把这个一元多项式分离成奇数多项式和偶数多项式，要求利用原链表空间，我编写了下面的算法，但是
并不能的出想要的结果，实在找不出错误了，所以请大家帮帮忙找出这个程序中的错误*/

#include<stdio.h>
#include<malloc.h>
typedef struct Polynode
{
    int coef;
    int exp;
    struct Polynode *next;
}Polynode,*Polylist;

Polylist InitPoly(Polylist *L)
{
    *L=(Polynode *)malloc(sizeof(Polynode));
    (*L)->next=*L;
    return *L;
}     /*初始化循环链表*/

Polylist InsPoly(Polylist L,int c,int e)
{
    
    Polynode *p,*s;
    p=L;
    while(p->next!=L)
        p=p->next;
    s=(Polynode *)malloc(sizeof(Polynode));
    s->coef=c;
    s->exp=e;
    s->next=L;
    p->next=s;
    return L;
}    /*循环链表元素的插入*/

Polylist DeletePoly(Polylist L,int *c,int *e)
{
    Polynode *r;
    r=L->next;
    L->next=r->next;
    *c=r->coef;
    *e=r->exp;
    free(r);
    return L;
}    /*循环链表元素的删除*/

void PrintPoly(Polylist L)
{
    Polynode *p;
    p=L->next;
    if(p==L)printf("多项式无值\n");
    else
    {
        printf("%dx^%d",p->coef,p->exp);
        p=p->next;
        while(p!=L)
        {
            printf("+%dx^%d",p->coef,p->exp);
            p=p->next;
        }
    }
}      /*链表元素的输出*/



void main()
{
    int c,e,n=1;
    Polynode *p;
    Polylist A,Odd,Eve;
    InitPoly(&A);
    printf("请输入多项式链表元素（多项式指数递增输入并以0，0结束）:");
    printf("第%d项系数:",n);
    scanf("%d",&c);
    printf("指数:");
    scanf("%d",&e);
    n++;
    while(c||e)    /*当系数和指数有一项不为0那么循环while语句*/
    {
        InsPoly(A,c,e);
        printf("第%d项系数:",n);
        scanf("%d",&c);
        printf("指数:");
        scanf("%d",&e);
        n++;

    }
    printf("原始多项式是：");
    PrintPoly(A);
    Odd=A;
    Odd->next=Odd;      
    Eve=A;
    Eve->next=Eve;     /*利用原链表空间创建并初始化2个新链表储存奇数多项式和偶数多项式*/
    p=A->next;
    while(p!=A)     /*如果p不等于头指针执行while语句*/
    {
        if((p->exp)%2==1)
        {
            DeletePoly(A,&c,&e);       
            InsPoly(Odd,c,e);     /*如果p指向的结点的指数是奇数，删除此结点并把此结点插入奇数链表中*/
        }
        else if((p->exp)%2==0)
        {
            DeletePoly(A,&c,&e);
            InsPoly(Eve,c,e);   /*如果p指向的结点的指数是偶数，删除此结点并把此结点插入偶数链表中*/
        }
        p=p->next;   
    }
    printf("\n奇数多项式是：");
    PrintPoly(Odd);
    printf("\n偶数多项式是：");
    PrintPoly(Eve);
}