/*9.
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) = 6x2y2z-4yz5+3x3yz+2xy5z-2xyz3
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 operation */
#include<stdio.h>
#include<stdlib.h>
#include<math.h>
struct node // polynomial node
{
int coef;
int x,y,z;
struct node *link;
};
typedef struct node *NODE;
NODE getnode() // create a node
{
NODE x;
x=(NODE)malloc(sizeof(struct node));
return x;
} // end of getnode
NODE readpoly()
{
NODE temp,head,cur;
char ch;
head=getnode(); // create a head node and set all values to -1 it is similar
to FIRST in SLL program
head->coef=-1;
head->x=-1;
head->y=-1;
head->z=-1;
head->link=head; // self reference
do
{
temp=getnode(); // create a polynomial node
printf("\nEnter the coefficient and exponent in decreasing order\
n");
scanf("%d%d%d%d",&temp->coef,&temp->x,&temp->y,&temp->z );
cur=head;
while(cur->link!=head) // find the last node
cur=cur->link;
cur->link=temp; // connect new node to the last node
temp->link=head; // point back to head
printf("\nDo you want to enter more coefficients(y/n)");
fflush(stdin); // to clear the stdin buffer
scanf("%c",&ch);
} while(ch =='y' || ch == 'Y');
return head; // return the polynomial list
} // end of readpoly
int compare(NODE a,NODE b) // function to compare the A and B polynomial nodes
{
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;
} // end of compare
void attach(int cf,int x1,int y1, int z1, NODE *ptr) // function to attach the A
and B polynomial node to C Polynomial
{
NODE temp;
temp=getnode();
temp->coef=cf;
temp->x=x1;
temp->y=y1;
temp->z=z1;
(*ptr)->link=temp;
*ptr=temp;
} // end of attach
NODE addpoly(NODE a,NODE b) // function to add polynomial A and B i.e, C=A+B
{
NODE starta,c ,lastc;
int sum,done=0;
starta=a;
a=a->link;
b=b->link;
c=getnode(); // create list C to store A+B
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); // repeate until not done
lastc->link=c; // point back to head of C
return c; // return answer
}
void print(NODE ptr) // to print the polynomial
{
NODE cur;
cur=ptr->link;
while(cur!=ptr) // To print from HEAD node till END node
{
printf("%d*x^%d*y^%d*z^%d",cur->coef,cur->x, cur->y, cur->z);
cur=cur->link; // move to next node
if (cur!=ptr)
printf(" + ");
}
} // end of print
void evaluate(NODE ptr) // function to evaluate the final polynomial
{
int res=0;
int x,y,z, ex,ey,ez,cof;
NODE cur;
printf("\nEnter the values of x, y,z"); // read values of X, Y and Z
scanf("%d", &x);
scanf("%d", &y);
scanf("%d", &z);
cur=ptr->link; // start with HEAD
while(cur!=ptr) // Repeat until the end of list
{
ex=cur->x; // exponent of x
ey=cur->y; // exponent of y
ez=cur->z; // exponent of z
cof=cur->coef; // coefficient
res+=cof*pow(x,ex)*pow(y,ey)*pow(z,ez); // compute result for
each polynomial
cur=cur->link; // move to next node
}
printf("\nresult: %d",res);
} // end of evaluate
void main(void)
{
int i, ch;
NODE a=NULL,b,c;
while(1)
{
printf("\n1: Represent first polynomial A");
printf("\n2: Represent Second polynomial B");
printf("\n3: Display the polynomial A");
printf("\n4: Display the polynomial B");
printf("\n5: Add A & B polynomials"); // C=A+B
printf("\n6: Evaluate polynomial C");
printf("\n7: Exit");
printf("\n Enter your choice: ");
scanf("%d",&ch);
switch(ch)
{
case 1: printf("\nEnter the elements of the polynomial A");
a=readpoly();
break;
case 2:printf("\nEnter the elements of the polynomial B");
b= readpoly();
break;
case 3: print(a); // display polynomial A
break;
case 4:print(b); // display polynomial A
break;
case 5: c=addpoly(a,b); // C=A+B
printf("\nThe sum of two polynomials is: ");
print(c); // display polynomial C
printf("\n");
break;
case 6:evaluate(c); // Evaluate polynomial C
break;
case 7: return;
default: printf("\nInvalid choice!\n");
} //end of switch
} // end of while
} // end of main
