9. Polynomial.c

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
#define COMPARE(x, y) ( (x == y) ? 0 : (x > y) ? 1 : -1)

struct node
{
    int coef;
    int xexp, yexp, zexp;
    struct node *link;
};
typedef struct node *NODE;

NODE getnode()
{
    NODE newnode;
    newnode = (NODE) malloc(sizeof(struct node));
    if(newnode == NULL){
        printf("Running out of memory \n");
            return NULL;
    }
       return newnode;
}

NODE attach(int coef, int xexp, int yexp, int zexp, NODE head)
{
    NODE temp, cur;
    temp = getnode();
    temp->coef = coef;
    temp->xexp = xexp;
    temp->yexp = yexp;
    temp->zexp = zexp;
    cur = head->link;
   while(cur->link != head){
        cur = cur->link;
        }
      cur->link = temp;
      temp->link = head;
        return head;
}

NODE read_poly(NODE head)
{
    int i, j, coef, xexp, yexp, zexp, n;
    printf("\nEnter the no of terms in the polynomial:");
    scanf("%d", &n);
    for(i=1; i<=n; i++){
        printf("\nEnter the %d term:\n",i);
        printf("Coefficient = ");
        scanf("%d", &coef);
        printf("Enter Power(x) Power(y) and Power(z):");
        scanf("%d", &xexp);
        scanf("%d", &yexp);
        scanf("%d", &zexp);
        head = attach(coef, xexp, yexp, zexp, head);
    }
        return head;
}

void display(NODE head)
{
    NODE temp;
        if(head->link == head){
            printf("\nPolynomial does not exist.");
             return;
    }
     temp = head->link;

    while(temp != head){
        printf("%dx^%dy^%dz^%d", temp->coef, temp->xexp, temp->yexp, temp->zexp);
        temp = temp->link;
        if(temp != head)
            printf(" + ");
    }
}

int poly_evaluate(NODE head)
{
    int x, y, z, sum = 0;
    NODE poly;
    printf("\nEnter the value of x,y and z: ");
    scanf("%d %d %d", &x, &y, &z);
    poly = head->link;
    while(poly != head){
        sum += poly->coef * pow(x,poly->xexp)* pow(y,poly->yexp) * pow(z,poly->zexp);
        poly = poly->link;
    }
      return sum;
}

NODE poly_sum(NODE head1, NODE head2, NODE head3)
{
    NODE a, b;
    int coef;
    a = head1->link;
    b = head2->link;
  while(a!=head1 && b!=head2){
      while(1){
        if(a->xexp == b->xexp && a->yexp == b->yexp && a->zexp == b->zexp)
       {
            coef = a->coef + b->coef;
            head3 = attach(coef, a->xexp, a->yexp, a->zexp, head3);
            a = a->link;
            b = b->link;
            break;
       } 
        if(a->xexp!=0 || b->xexp!=0)
       {
            switch(COMPARE(a->xexp, b->xexp))
    {
        case -1 :  head3 = attach(b->coef, b->xexp, b->yexp, b->zexp, head3);
                       b = b->link;
                       break;

        case 0 :   if(a->yexp > b->yexp)
            {
                head3 = attach(a->coef, a->xexp, a->yexp, a->zexp, head3);
                a = a->link;
                break;
            }
             else if(a->yexp < b->yexp)
            {
                head3 = attach(b->coef, b->xexp, b->yexp, b->zexp, head3);
                b = b->link;
                break;
            }
            else if(a->zexp > b->zexp)
            {
                head3 = attach(a->coef, a->xexp, a->yexp, a->zexp, head3);
                a = a->link;
                break;
            }
            else if(a->zexp < b->zexp)
            {
                head3 = attach(b->coef, b->xexp, b->yexp, b->zexp, head3);
                b = b->link;
                break;
            }
        case 1 :head3 = attach(a->coef,a->xexp,a->yexp,a->zexp,head3);
                a = a->link;
                break;
    } 
            break;
        } 
    if(a->yexp!=0 || b->yexp!=0)
  {
        switch(COMPARE(a->yexp, b->yexp))
    {
        case -1 : head3 = attach(b->coef, b->xexp, b->yexp, b->zexp, head3);
                  b = b->link;
                  break;
        case 0 :if(a->zexp > b->zexp){
                head3 = attach(a->coef, a->xexp, a->yexp, a->zexp, head3);
                a = a->link;
                break;
            }
              else if(a->zexp < b->zexp){
                head3 = attach(b->coef, b->xexp, b->yexp, b->zexp, head3);
                b = b->link;
                break;
            }
        case 1 :head3 = attach(a->coef, a->xexp, a->yexp, a->zexp, head3);
                a = a->link;
                break;
    }
            break;
  }
    if(a->zexp!=0 || b->zexp!=0)
    {
    switch(COMPARE(a->zexp,b->zexp)){
        case -1 :head3 = attach(b->coef,b->xexp,b->yexp,b->zexp,head3);
                 b = b->link;
                 break;
        case 1 :head3 = attach(a->coef, a->xexp, a->yexp, a->zexp, head3);
                a = a->link;
                break;
    }
         break;
        }
    }
}
  while(a!= head1)
    {
        head3 = attach(a->coef,a->xexp,a->yexp,a->zexp,head3);
        a = a->link;
    }
  while(b!= head2)
    {
        head3 = attach(b->coef,b->xexp,b->yexp,b->zexp,head3);
        b = b->link;
    }
    return head3;
}

void main()
{
  NODE head, head1, head2, head3;
  int res, ch;
  head =  getnode();    
  head1 = getnode();    
  head2 = getnode();    
  head3 = getnode();    

  head->link=head;
  head1->link=head1;
  head2->link=head2;
  head3->link= head3;

  while(1)
  {
      printf("\nPOLYNOMIAL :-");
      printf("\n1.Evaluate a Polynomial P(x,y,z)");
      printf("\n2.Sum of two polynomials POLY1(x,y,z) & POLY2(x,y,z)");
      printf("\n3.Exit");
      printf("\nEnter your choice:");
      scanf("%d",&ch);
    switch(ch)
    {
        case 1:printf("\nPolynomial evaluation P(x,y,z)\n");
              head = read_poly(head);
              printf("\nRepresentation of Polynomial for evaluation: \n");
              display(head);
              res = poly_evaluate(head);
              printf("\nResult of polynomial evaluation is : %d \n", res);
                break;

        case 2:printf("\nEnter the POLY1(x,y,z):  \n");
                head1 = read_poly(head1);
                printf("\nPolynomial 1 is:  \n");
                display(head1);
                printf("\nEnter the POLY2(x,y,z):  \n");
                head2 = read_poly(head2);
                printf("\nPolynomial 2 is: \n");
                display(head2);
                printf("\nPolynomial addition result: \n");
                head3 = poly_sum(head1,head2,head3);
                display(head3);
                break;
        case 3: exit(0);
      }
    }
}