牛顿迭代法解一元多项式   运行了几次都是做到求导的地方就崩溃了
#include<stdio.h>
#include<math.h>
#include<stdlib.h>
typedef struct Misaki{
     double xishu;
     double zhishu;
     double DX;
     double DZ;
     Misaki *next;
}shi;
 
shi*creat()
 {
  double xi,zhi;
  shi* head,*last,*work;
  head=(shi*)malloc(sizeof(shi));
  last=head;
  printf("系数:");
  scanf("%lf",&xi);
   printf("指数:");
  scanf("%lf",&zhi);
  while(zhi!=0)
  {
    work=(shi*)malloc(sizeof(shi));
    work->xishu=xi;
    work->zhishu=zhi;
    last->next=work;
    last=work;
     printf("系数:");
  scanf("%lf",&xi);
   printf("指数:");
  scanf("%lf",&zhi);
  }
   last->next=NULL;
   return head;
}
void qiudao(shi*head)
{shi*p;
 p=head;
 double newxi,newzhi;
 if(head==NULL||head->next==NULL)
  printf("没有导数\n");
  else{
   printf("导数为：");
   while(p!=NULL)
   {
     newxi=p->xishu;
     newzhi=p->zhishu;
     if(newzhi==0)
     {}
     else{//求导
      newxi=newzhi*newxi;
     newzhi=newzhi-1;
     printf("%.1lfx^%.1lf",newxi,newzhi);
     printf("+");
     p->DX=newxi;
     p->DZ=newzhi;
     p=p->next;}
   }
    newxi=p->xishu;
    newzhi=p->zhishu;
    if(newzhi==0)
     {newzhi=0;
      newxi=0;}
     else{
         newxi=newzhi*newxi;
     newzhi=newzhi-1;
    printf("%.1lfx",newxi);
   printf("x^%.1lf\n",newzhi);
    p->DX=newxi;
    p->DZ=newzhi;
  }
  }
}
void Cal (shi*head)//设初始值为5
{
    shi *p;
    p=head;
    double x=5;
    double x0=0;
    double xielv=0;
    double xdot=0;
    for(;;)
    {
    //求斜率
    while(p!=NULL)
    {
        xielv+=p->DX*pow(x,p->DZ);
        p=p->next;
    }xielv+=p->next->DX*pow(x,p->next->DZ);
    if(xielv==0)
    {
    printf("迭代过程中导数为0");
    goto s;
    }
    //求多项式
    p=head;
    while(p!=NULL)
    {
        x0+=p->xishu*pow(x,p->zhishu);
    }x0+=p->next->xishu*pow(x,p->next->zhishu);
    //求交点坐标
    xdot=x-(x0/xielv);
   
    if(fabs(x0-xdot)<0.01)
    break;
    s:
        
    x0=xdot;
    }
    printf("%lf",x0);

}
int main()
{
    shi*head;
     head=creat();
     qiudao(head);
      Cal (head);
       return 0;
}