poly.c

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
struct list
{
	int coef;
	int x;
	int y;
	int z;
	struct list *link;
};
typedef struct list *NODE;
#define MALLOC(p,s,t)\
	if(!(p=(t)malloc(s))){\
		fprintf(stderr,"insufficient Memory \n");\
		exit(0);\
	}
NODE readpoly(NODE);
NODE padd(NODE,NODE);
float evalpoly();
NODE attach(int,int,int,int,NODE);
void printpoly(NODE);

void main()
{
	NODE p1,p2,p3;
	int done=0;
	int choice;
	float result;
	int expx,expy,expz;
	while(!done)
	{
		printf("1.Polynomial Evaluation\t 2.Add polynomial \t 3.Exit \n");
		printf("Enter choice: ");
		scanf("%d",&choice);
		switch(choice)
		{
			case 1:result=evalpoly();
				printf("The polynomial result=%8.2f",result);
				break;

			case 2:MALLOC(p1,sizeof(struct list),NODE);
			MALLOC(p2,sizeof(struct list),NODE);
			p1->link=p1;
			p2->link=p2;
			printf("Enter polynomial a: \n");
			p1=readpoly(p1);
			printf("Enter polynomial b: \n");
			p2=readpoly(p2);
			p3=padd(p1,p2);
			printf("Resultant c: ");
			printpoly(p3);
			break;

			case 3:done=1;break;

			default: printf("illegal entry \n");
			break;
		}
	}
}

NODE readpoly(NODE p)
{
	int ce,expx,expy,expz;
	while(1)
	{
		printf("Enter coeff and expx,expy,expz(-1 for exponent x to terminate) : ");
		scanf("%d%d%d%d",&ce,&expx,&expy,&expz);
		if(expx==-1)
			break;
		p=attach(ce,expx,expy,expz,p);
	}
	return p;
}

NODE padd(NODE p1,NODE p2)
{
	NODE p3;
	NODE starta = p1;
	NODE startb = p2;
	int sum;
	MALLOC(p3,sizeof(struct list),NODE);
	p3->link=p3;
	p1=p1->link;
	p2=p2->link;
	while(p1 != starta && p2 != startb)
	{
		if(p1->x == p2->x && p1->y == p2->y && p1->z == p2->z)
		{
			sum=p1->coef+p2->coef;
			if(sum)
				p3=attach(sum,p1->x,p1->y,p1->z,p3);
			p1=p1->link;
			p2=p2->link;
		}
		else if(p1->x < p2->x)
		{
			p3=attach(p2->coef,p2->x,p2->y,p2->z,p3);
			p2=p2->link;
		}
		else if(p1->x > p2->x)
		{
			p3=attach(p1->coef,p1->x,p1->y,p1->z,p3);
			p1=p1->link;
		}
		else if(p1->y < p2->y)
		{
			p3=attach(p2->coef,p2->x,p2->y,p2->z,p3);
			p2=p2->link;
		}
		else if(p1->y > p2->y)
		{
			p3=attach(p1->coef,p1->x,p1->y,p1->z,p3);
			p1=p1->link;
		}
		else if(p1->z < p2->z)
		{
			p3=attach(p2->coef,p2->x,p2->y,p2->z,p3);
			p2=p2->link;
		}
		else if(p1->z > p2->z)
		{
			p3=attach(p1->coef,p1->x,p1->y,p1->z,p3);
			p1=p1->link;
		}
	}
	for(;p1 != starta;p1=p1->link)
		p3=attach(p1->coef,p1->x,p1->y,p1->z,p3);
	for(;p2 != startb;p2=p2->link)
		p3=attach(p2->coef,p2->x,p2->y,p2->z,p3);
	return p3;
}
NODE attach(int c,int expx,int expy,int expz,NODE header)
{
	NODE temp,q;
	MALLOC(temp,sizeof(struct list),NODE);
	temp->coef=c;
	temp->x=expx;
	temp->y=expy;
	temp->z=expz;
	q=header->link;
	while(q->link != header)
		q=q->link;
	q->link=temp;
	temp->link=header;
	return header;
}
float evalpoly()
{
	float sum=0;
	NODE p,start;
	float xval,yval,zval;
	int k,n=20;
	int terms[20]={6,2,2,1,-4,0,1,5,3,3,1,1,2,1,5,1,-2,1,1,3};
	MALLOC(p,sizeof(struct list),NODE);
	p->link=p;
	printf("Enter values for x,y,z: ");
	scanf("%f%f%f",&xval,&yval,&zval);
	for(k=0;k<n;k+=4)
		p=attach(terms[k],terms[k+1],terms[k+2],terms[k+3],p);
	start=p;
	p=p->link;
	do
	{
		sum+=p->coef*pow(xval,p->x)*pow(yval,p->y)*pow(zval,p->z);
		p=p->link;
	}
	while(p != start);
	return sum;
}
void printpoly(NODE header)
{
	NODE q;
	q=header->link;
	do
	{
	printf("%dx^%dy^%dz^%d+",q->coef,q->x,q->y,q->z);
	q=q->link;
	}
	while(q!=header);
	printf("\n");
}