Lab9.c

/*Design, Develop and Implement a Program in C for the following operations on
Singly Circular
Linked List (SCLL) with header nodes
a. Represent and Evaluate a Polynomial P(x,y,z) = 6x 2 y 2 z-4yz 5 +3x 3 yz+2xy
5 z-2xyz 3
b. Find the sum of two polynomials POLY1(x,y,z) and POLY2(x,y,z) and store the
result in
POLYSUM(x,y,z)
Support the program with appropriate functions for each of the above operations
*/
#include<stdio.h> //for standard input output function
#include<stdlib.h> //for memory allocation
#include<math.h> //mathematical functions
#include<conio.h>
struct node //create a structure for polynomial node. How a node should be to store a polynomial
{
int coef; //node should hold coefficient value
int x,y,z; // node should hold exponents of x,y,x
struct node *link; //contains address of next node
};
typedef struct node *NODE;
//function to create a node
NODE getnode()
{
NODE x;
x=(NODE)malloc(sizeof(struct node));
return x;
}
//function to read polynomial
NODE readpoly()
{
NODE temp,head,cur;
char ch;
head=getnode();
head->coef=-1;
head->x=-1;
head->y=-1;
head->z=-1;
head->link=head;
do
{
temp=getnode();
printf("\n Enter the coefficient and exponent in decreasing order");
scanf("%d%d%d%d",&temp->coef,&temp->x,&temp->y,&temp->z);
cur=head;
while(cur->link!=head)
cur=cur->link;
cur->link=temp;
temp->link=head;
printf("\n Do you want to enter more coefficients(y/n)");
fflush(stdin);
scanf("%c",&ch);
}while(ch=='y'||ch=='Y');
return head;
}
//display the polynomial expression
void print(NODE ptr)
{
NODE cur;
cur=ptr->link;
while(cur!=ptr)
{
printf("%d*x^%d*y^%d*z%d",cur->coef,cur->x,cur->y,cur->z);
cur=cur->link;
if(cur!=ptr)
{
printf("+");
}
}
}
//function to compare polynomials A and b
int compare(NODE a, NODE b)
{
if(a->x > b->x)
return 1;
else if(a->x < b->x)
return -1;
else if(a->y > b->y)
return 1;
else if(a->y < b->y)
return -1;
else if(a->z > b->z)
return 1;
else if(a->z < b->z)
return -1;
return 0;
}
//function ot attach the A nad B Polynomial node to C Polynomial
void attach(int cf, int x1, int y1, int z1, NODE *ptr)
{
NODE temp;
temp=getnode();
temp->coef=cf;
temp->x=x1;
temp->y=y1;
temp->z=z1;
(*ptr)->link=temp;
*ptr=temp;
}
//function to add polynomial A and B (C= A+B)
NODE addpoly(NODE a, NODE b)

{
NODE starta, c, lastc;
int sum, done=0;
starta=a;
a=a->link;
b=b->link;
c=getnode();
c->coef=-1;
c->x=-1;
c->y=-1;
c->z=-1;
lastc=c;
do
{
switch(compare(a,b))
{
case -1: attach(b->coef,b->x,b->y,b->z,&lastc);
b=b->link;
break;
case 0: if(starta==a)done=1;
else
{
sum=a->coef+b->coef;
if(sum)
attach(sum,a->x,a->y,a->z,&lastc);
a=a->link;
b=b->link;
}
break;
case 1: if(starta==a)
done=1;
attach(a->coef,a->x,a->y,a->z,&lastc);
a=a->link;
break;
}
}while(!done);
lastc->link=c;
return c;
}
//function to evaluate the final polynomial
void evaluate(NODE ptr)
{
int res=0;
int x,y,z,ex,ey,ez,cof;
NODE cur;
printf("\n Enter the values of x,y,z");
scanf("%d", &x);
scanf("%d", &y);
scanf("%d", &z);
cur=ptr->link;
while(cur!=ptr)
{
ex=cur->x;

ey=cur->y;
ez=cur->z;
cof=cur->coef;
res+=cof*pow(x,ex)*pow(y,ey)*pow(z,ez);
cur=cur->link;
}
printf("\nresult: %d",res);
}
void main()
{
system("cls");
int i, ch;
NODE a=NULL,b,c;
while(1)
{
printf("\n 1:Represent first polynomial A");
printf("\n 2:Represent second polynomial B");
printf("\n 3:Display the polynomial A");
printf("\n 4:Display the polynomial B");
printf("\n 5:Add A & B polynomials");
printf("\n 6:Evaluate polynomial C");
printf("\n 7:Exit");
printf("\n Enter your choice:");
scanf("%d",&ch);
switch(ch)
{
case 1: printf("\n Enter the elements of the polynomial A");
a=readpoly();
break;
case 2: printf("\n Enter the elements of the polynomial B");
b=readpoly();
break;
case 3: print(a);
break;
case 4: print(b);
break;
case 5: c=addpoly(a,b);
printf("\n The aum of two polynomials is:");
print(c);
printf("\n");
break;
case 6: evaluate(c);
break;
case 7: return;
default: printf("\n Invalid choice:\n");
}
}
}