Data Structure lab

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

typedef struct node {
    int x, y, z, coeff;
    struct node *link;
} *NODE;

NODE getNode() {
    NODE temp = (NODE)malloc(sizeof(struct node));
    temp->link = temp;
    return temp;
}

NODE insertEnd(NODE head, int x, int y, int z, int c) {
    NODE temp = getNode();
    temp->x = x; temp->y = y; temp->z = z; temp->coeff = c;

    if (head->link == head) {
        head->link = temp;
        temp->link = head;
    } else {
        NODE cur = head->link;
        while (cur->link != head)
            cur = cur->link;
        cur->link = temp;
        temp->link = head;
    }
    return head;
}

void display(NODE head) {
    NODE temp = head->link;
    if (temp == head) {
        printf("Polynomial is empty.\n");
        return;
    }
    while (temp != head) {
        printf("%+dx^%dy^%dz^%d ", temp->coeff, temp->x, temp->y, temp->z);
        temp = temp->link;
    }
    printf("\n");
}

int evaluate(NODE head, int x, int y, int z) {
    int sum = 0;
    NODE temp = head->link;
    while (temp != head) {
        sum += temp->coeff * pow(x, temp->x) * pow(y, temp->y) * pow(z, temp->z);
        temp = temp->link;
    }
    return sum;
}

NODE addPoly(NODE p1, NODE p2) {
    NODE result = getNode();
    NODE t1 = p1->link, t2;
    while (t1 != p1) {
        insertEnd(result, t1->x, t1->y, t1->z, t1->coeff);
        t1 = t1->link;
    }
    t2 = p2->link;
    while (t2 != p2) {
        NODE r = result->link;
        int found = 0;
        while (r != result) {
            if (r->x == t2->x && r->y == t2->y && r->z == t2->z) {
                r->coeff += t2->coeff;
                found = 1;
                break;
            }
            r = r->link;
        }
        if (!found)
            insertEnd(result, t2->x, t2->y, t2->z, t2->coeff);
        t2 = t2->link;
    }
    return result;
}

int main() {
    NODE P = getNode();
    // a. Representing P(x,y,z) = 6x^2y^2z - 4yz^5 + 3x^3yz + 2xy^5z - 2xyz^3
    insertEnd(P, 2,2,1,6);
    insertEnd(P, 0,1,5,-4);
    insertEnd(P, 3,1,1,3);
    insertEnd(P, 1,5,1,2);
    insertEnd(P, 1,1,3,-2);
    
    printf("Polynomial P(x,y,z):\n");
    display(P);

    int x=1, y=2, z=1;
    printf("Evaluated at x=%d y=%d z=%d: %d\n", x, y, z, evaluate(P, x, y, z));

    // b. Add two polynomials
    NODE POLY1 = getNode();
    insertEnd(POLY1, 1, 1, 1, 2);
    insertEnd(POLY1, 0, 1, 1, 3);

    NODE POLY2 = getNode();
    insertEnd(POLY2, 1, 1, 1, 4);
    insertEnd(POLY2, 2, 1, 0, 5);

    NODE POLYSUM = addPoly(POLY1, POLY2);
    printf("\nPOLY1:\n"); display(POLY1);
    printf("POLY2:\n"); display(POLY2);
    printf("POLY1 + POLY2:\n"); display(POLYSUM);

    return 0;
}



               


  

Polynomial P(x,y,z):
+6x^2y^2z^1 -4x^0y^1z^5 +3x^3y^1z^1 +2x^1y^5z^1 -2x^1y^1z^3 
Evaluated at x=1 y=2 z=1: 82

POLY1:
+2x^1y^1z^1 +3x^0y^1z^1 
POLY2:
+4x^1y^1z^1 +5x^2y^1z^0
POLY1 + POLY2:
+6x^1y^1z^1 +3x^0y^1z^1 +5x^2y^1z^0