c实现一元多项式加乘

这学期数据结构老师是学校里最严格的
而我发现自己落后了
别人早就当天就把布置的实验完成了
我还........
惭愧
连夜补上 虽然自知不好
仅作纪念 要加油了

/***************************************************************************
* Copyright (C) 2008 by root *
多项式 gcc 版本 4.1.2 20070925 (Red Hat 4.1.2-33)

***************************************************************************/

#include <stdio.h>
#include <stdlib.h>

typedef struct node
{
double coef;
int expn;
struct node * next;
}lnode,*lklist;

int compare ( int,int );
void InsertLklist ( lklist L,double coef,int expn ); //有序插入
void CreateLklist ( lklist *L );
void InitLklist ( lklist *L );
void PrintPolyn ( lklist L );
int DeleteLklist(lklist L,int expn);
lklist add(lklist a,lklist b);
lklist mul(lklist a,lklist b);
void ClearLklist(lklist L);
void show_function(); //显示程序功能菜单
void DestoryLklist(lklist L);

void DestoryLklist( lklist L)
{
lklist p;
lklist q=L;
while(L->next)
{
p=L->next;
L->next=p->next;
free(p);
}
free(q);
return;

}

void show_function()
{
printf("/n/n*****************请按数字键选择功能**********************/n");
printf("/t1 －－－ 创建多项式a/t/t");
printf("/t2 －－－ 创建多项式b/n");
printf("/t3 －－－ 显示a+b/t/t");
printf("/t4 －－－ 显示a*b/n");
printf("/t5 －－－ 退出/n");
}

void ClearLklist(lklist L)
{
lklist p;
while(L->next)
{
p=L->next;
L->next=p->next;
free(p);
}
return;
}

lklist mul(lklist a,lklist b)
{
lklist c,d,e,f;
InitLklist( &c);

e=a->next;f=b->next;
while(e!=NULL)
{
f=b->next;
while(f!=NULL)
{
InsertLklist( c,(e->coef)*(f->coef),(e->expn)+(f->expn));
f=f->next;
}
e=e->next;
}
return c;

}

lklist add(lklist a,lklist b)
{
lklist c,d;
InitLklist(&c);
d=a->next;

while(d!=NULL)
{
InsertLklist( c,d->coef,d->expn);
d=d->next;
}
d=b->next;
while(d!=NULL)
{
InsertLklist( c,d->coef,d->expn);
d=d->next;
}
return c;
}

int DeleteLklist(lklist L,int expn)
{
lklist p,q;
p=L;
while(p!=NULL&&p->expn!=expn)
{
q=p;
p=p->next;
}
if(p!=NULL&&p->expn==expn)
{
q->next=p->next;
free(p);
return 1;
}
else
{
return 0;
}
}

void PrintPolyn ( lklist L )

{
lklist p;
p=L->next;
while ( p!=NULL )
{
if(p->expn!=0)
{
if(p->coef==1)
{
if(p->expn!=1)
{
printf ( "x^%d",p->expn );}
else
{
printf ( "x");
}
}
else
{
if(p->expn!=1)
{
printf ( "%lfx^%d", p->coef,p->expn );}
else
{
printf ( "%lfx", p->coef);

}
}

}
else
{
printf ( "%lf",p->coef );
}

if ( p->next!=NULL )
{
if(p->next->coef>0)
{
printf ( " + " );
}
else
{
printf ( " " );
}

}
p=p->next;
}

printf("/n");
}

void CreateLklist ( lklist *L )
{
double coef;
int expn;
InitLklist ( L );
int flag=1;
while ( flag )
{
printf ( "输入插入的系数和次数 以 , 隔开/n" );
scanf ( "%lf,%d",&coef,&expn );
getchar();

InsertLklist ( *L,coef,expn );
printf ( " c 继续输入 q退出/n" );
if ( getchar()!='c' )
{
getchar();
break;
}
getchar();
}
}

void InsertLklist ( lklist L,double coef,int expn )
{

lklist p,q,s;
p=L;
q=L;

while((p->expn)<expn&&p->next!=NULL)
{
q=p;
p=p->next;
}

//printf("dang qian p %lf %d/n",p->coef,p->expn);
if(expn<q->expn||(p==NULL))
{

printf("输入数据有误 不能插入/n");
}

if(expn==(p->expn))
{
p->coef=p->coef+coef;
if(p->coef==0)
{
DeleteLklist(L,p->expn);
}

return;
}
if(expn>(p->expn))
{
s= ( lklist ) malloc ( sizeof ( lnode ) );
s->expn=expn;
s->coef=coef;
//printf("dangqian s %lf , %d/n",s->coef,s->expn);
s->next=p->next;
p->next=s;

//printf("dddddangqian sddddp %lf , %d/n",p->next->coef,p->next->expn);
//PrintPolyn ( L );
return;
}

if(expn>(q->expn))
{
s= ( lklist ) malloc ( sizeof ( lnode ) );
s->expn=expn;
s->coef=coef;
//printf("dangqian s %lf , %d/n",s->coef,s->expn);
s->next=q->next;
q->next=s;
//printf("dddddangqian sddddq %lf , %d/n",q->next->coef,q->next->expn);
//PrintPolyn ( L );
return;
}

}

void InitLklist ( lklist *L )
{
lklist s;
s= ( lklist ) malloc ( sizeof ( lnode ) );
s->coef=0;
s->expn=-1;
s->next=NULL;
*L=s;
}

int compare ( int a,int b )
{
if ( a==b )
{
return 0;
}
if ( a>b )
{
return 1;
}
if ( a<b )
{
return -1;
}
}

int main ( int argc, char *argv[] )
{
lklist a,b,c;
InitLklist(&c);

int flag=1;
show_function();
char x;
while(flag)
{
x=getchar();
getchar();
switch(x)
{
case '1':
CreateLklist(&a);
printf("多项式a创建成功 显示如下: /n");
PrintPolyn( a);
show_function();

break;
case '2':
CreateLklist(&b);
printf("多项式b创建成功 显示如下: /n");
PrintPolyn( b);
show_function();

break;
case '3':
ClearLklist(c);
c=add(a,b);
PrintPolyn( c);
show_function();

break;
case '4':
ClearLklist( c);
c=mul( a,b);
PrintPolyn( c);
show_function();
break;
case '5':
DestoryLklist( a);
DestoryLklist( b);
DestoryLklist( c);
flag=0;
break;
default :

printf("Chose error!/n");
break;
}
}

return EXIT_SUCCESS;
}