C - Program to Implement Polynomial using a circular linked list
#include <stdio.h>
#include <conio.h>
#include <math.h>
typedef struct node
{
int power;
float coeff;
struct node *next;
}node;
node * insert(node *head,int power1,float coeff1);
node * create();
node * padd(node *p1,node *p2);
node * pmul(node *p1,node *p2);
float eval(node *p1,float x);
void print(node *head);
node *insert(node *head,int power1,float coeff1)
{
node *p,*q;
/*terms are stored in decreasing order of power*/
/*pointer is used to locate the correct place of insertion.
pointer p is used to store the address of the node created for
the current term.If a term with same power is found,coefficients
are added*/
p=(node*) malloc(sizeof(node));
p->power=power1;
p->coeff=coeff1;
p->next=NULL;
if(head==NULL) //Empty linked list
{
head=p;
head->next=head;
return(head);
}
if(power1<head->power)//lowest power,inserted at the end
{
p->next=head->next;
head->next=p;
head=p;
return(head);
}
if(power1==head->power) //add coefficients
{
head->coeff=head->coeff+coeff1;
return(head);
}
q=head;
while(q->next!=head && power1<=q->next->power) //locate the postion for insertion
q=q->next;
if(p->power==q->power)
q->coeff=q->coeff+coeff1;
else
{
p->next=q->next;
q->next=p;
}
return(head);
}
node *create()
{
int n,i,power1;
float coeff1;
node *head=NULL;
printf("\nEnter No. of Terms:");
scanf("%d",&n);
printf("\nenter a term as a tuple of (power,coefficient) : ");
for(i=1;i<=n;i++)
{
scanf("%d%f",&power1,&coeff1);
head=insert(head,power1,coeff1);
}
return(head);
}
node * padd(node *p1,node *p2)
{
node *p;
node *head=NULL;
int power;float coeff;
p=p1->next;
do //insert the first polynomial
{
head=insert(head,p->power,p->coeff);
p=p->next;
} while(p!=p1->next);
p=p2->next;
do //insert the second polynomial
{
head=insert(head,p->power,p->coeff);
p=p->next;
} while(p!=p2->next);
return(head);
}
node *pmul(node *p1,node *p2)
{
node *head1,*head2;
node *head=NULL;
head2=p2->next;
do //for every term of the second polynomial
{
head1=p1->next;
do //multiply with every term of the first polynomial
{
// for(p=head1;p!=NULL;p=p->next)
head=insert(head,head1->power+head2->power,head1->coeff * head2->coeff);
head1=head1->next;
}while(head1!=p1->next);
head2=head2->next;
}while(head2!=p2->next);
return(head);
}
float eval(node *head,float x)
{
float value=0.00;
node *p;
p=head->next;
do
{
value=value+p->coeff * pow(x,p->power);
p=p->next;
}while(p!=head->next);
return(value);
}
void print( node *head)
{
node *p;
p=head->next;
printf("\n");
do
{
printf("%6.2fx^%d ",p->coeff,p->power);
p=p->next;
}while(p!=head->next);
}
void main()
{
node *p1,*p2,*p3;
int op;
float value,x;
p1=p2=p3=NULL;
clrscr();
do
{
printf("\n1)Create first polynomial");
printf("\n2)Create second polynomial");
printf("\n3)Print first polynomial");
printf("\n4)Print second polynomial");
printf("\n5)Add\n6)Multiply\n7)Evaluate First Polynomial\n8)Quit");
printf("\nEnter Your Choice: ");
scanf("%d",&op);
switch(op)
{
case 1: p1=create();break;
case 2: p2=create();break;
case 3: print(p1);break;
case 4: print(p2);break;
case 5: p3=padd(p1,p2);
print(p3);break;
case 6: p3=pmul(p1,p2);
print(p3);break;
case 7: printf("\nEnter the value of X:");
scanf("%f",&x);
value=eval(p1,x);
printf("\nEvaluated value = %6.2f",value);
break;
}
}while(op!=8);
}
