Untitled

#include<stdio.h>
#include<stdlib.h>
struct node
{
    int data;
    struct node *next;
};
struct node *front;
struct node *rear;
void push();
void pop();
void display();
void top();
int isEmpty();
int size();
int main ()
{
    int choice = 0;
    while(choice != 7)
    {   int sz =0, flag=0;
        printf("\nMain Menu\n");
        printf("\n1.push an element\n2.pop an element\n3.top value\n4.Display the queue\n5.size\n6.isEmpty\n7.Exit");
        printf("\nEnter your choice : ");
        fflush(stdin);
        scanf("%d",&choice);
        switch(choice)
        {
            case 1:
                display();
                push();
                display();
                break;

            case 2:
                display();
                pop();
                display();
                break;
            case 3:
                top();
                break;
            case 4:
                display();
                break;
            case 5:
            {
                sz = size();
                printf("Size of queue is: %d \n", sz);
                break;
            }
            case 6:
            {
                flag = isEmpty();
                if(flag == 1)
                    printf("queue is empty. \n");
                else
                    printf("queue is not empty. \n");
                break;
            }

            default:
                printf("\nEnter valid choice : \n");
        }
    }
    return 0;
}

void push()
{
    struct node *ptr;
    int item;

    ptr = (struct node *) malloc (sizeof(struct node));
    if(ptr == NULL)
    {
        printf("\nOVERFLOW\n");
        return;
    }
    else
    {
        printf("\nEnter value : ");
        scanf("%d",&item);
        ptr -> data = item;
        if(front == NULL)
        {
            front = ptr;
            rear = ptr;
            front -> next = NULL;
            rear -> next = NULL;
        }
        else
        {
            rear -> next = ptr;
            rear = ptr;
            rear->next = NULL;
        }
    }
}

void pop()
{
    struct node *ptr;
    if(front == NULL)
    {
        printf("\nUNDERFLOW\n");
        return;
    }
    else
    {
        ptr = front;
        front = front -> next;
        free(ptr);
    }
}
void display()
{
    struct node *ptr;
    ptr = front;
    if(front == NULL)
    {
        printf("\nEmpty queue\n");
    }
    else
    {   printf("\nValues are : \n");
        while(ptr != NULL)
        {
            printf("\n%d\n",ptr -> data);
            ptr = ptr -> next;
        }
    }
}
void top()
{
    struct node *ptr;
    ptr = front;
    if(front == NULL)
    {
        printf("\nEmpty queue\n");
    }
    else
         printf("\n%d\n",ptr -> data);
}

int size()
{
    int cnt = 0;
    struct node* ptr;
    ptr = front;
    while(ptr != NULL)
    {
        cnt++;
        ptr = ptr -> next;
    }
    return cnt;
}

int isEmpty()
{
    int flag = 0;
    if(front == NULL)
        flag = 1;
    else
        flag = 0;
    return flag;

}


//polynomial
#include<stdio.h>
#include<stdlib.h>

struct Node
{
	int coeff;
	int pow;
	struct Node* next;
};

void readPolynomial(struct Node** poly)
{
	int coeff, exp, cont;
	struct Node* temp = (struct Node*)malloc(sizeof(struct Node));
	*poly = temp;
	do{
		printf("\n Coeffecient: ");
		scanf("%d", &coeff);
		printf("\n Exponent: ");
		scanf("%d", &exp);
		temp->coeff = coeff;
		temp->pow = exp;
		temp-> next = NULL;
		printf("\nHave more terms? 1 for y and 0 for no: ");
		scanf("%d", &cont);
		if(cont)
		{
			temp->next = (struct Node*)malloc(sizeof(struct Node));
			temp = temp->next;
			temp->next = NULL;
		}
	}while(cont);
}

void displayPolynomial(struct Node* poly)
{
	printf("\nPolynomial expression is: ");
	while(poly != NULL)
	{
		printf("%dX^%d", poly->coeff, poly->pow);
		poly = poly->next;
		if(poly != NULL)
			printf("+");
	}
}

void addPolynomials(struct Node** result, struct Node* first, struct Node* second)
{
 	struct Node* temp = (struct Node*)malloc(sizeof(struct Node));
 	temp->next = NULL;
 	*result = temp;
 	while(first && second)
 	{
 		if(first->pow > second->pow)
 		{
 			temp->coeff = first->coeff;
 			temp->pow = first->pow;
 			first = first->next;
 		}
 		else if(first->pow < second->pow)
 		{
 			temp->coeff = second->coeff;
 			temp->pow = second->pow;
 			second = second->next;
 		}
 		else
 		{
 			temp->coeff = first->coeff + second->coeff;
 			temp->pow = first->pow;
 			first = first->next;
 			second = second->next;
 		}

 		if(first && second)
 		{
 			temp->next = (struct Node*)malloc(sizeof(struct Node));
 			temp = temp->next;
 			temp->next = NULL;
 		}
 	}
 	while(first || second)
 	{
 		temp->next = (struct Node*)malloc(sizeof(struct Node));
 		temp = temp->next;
 		temp->next = NULL;

 		if(first)
 		{
 			temp->coeff = first->coeff;
 			temp->pow = first->pow;
 			first = first->next;
 		}

 		else if(second)
 		{
 			temp->coeff = second->coeff;
 			temp->pow = second->pow;
 			second = second->next;
 		}
 	}
}

int main()
{

	struct Node* first = NULL;
	struct Node* second = NULL;
	struct Node* result = NULL;

	printf("\nEnter the corresponding data:-\n");
	printf("\nFirst polynomial:\n");
	readPolynomial(&first);
	displayPolynomial(first);
	printf("\nSecond polynomial:\n");
	readPolynomial(&second);
	displayPolynomial(second);
	addPolynomials(&result, first, second);
	displayPolynomial(result);
	return 0;
}