Stack_using_linked.c

#include <stdio.h>
#include <stdlib.h>
struct node{
	int info;
	struct node *ptr;
}*top,*top1,*temp;
int count = 0;
void push(int data){
	if (top == NULL){
		top =(struct node *)malloc(1*sizeof(struct node));
		top->ptr = NULL;
		top->info = data;
	}
	else{
		temp =(struct node *)malloc(1*sizeof(struct node));
		temp->ptr = top;
		temp->info = data;
		top = temp;
	}
	count++;
	printf("Node is Inserted\n\n");
}
int pop(){
	top1 = top;
	if (top1 == NULL){
		printf("\nStack Underflow\n");
		return -1;
	}
	else
		top1 = top1->ptr;
	int popped = top->info;
	free(top);
	top = top1;
	count--;
	return popped;
}
void display(){
	top1 = top;
	if (top1 == NULL){
		printf("\nStack Underflow\n");
		return;
	}
	printf("The stack is \n");
	while (top1 != NULL){
		printf("%d--->", top1->info);
		top1 = top1->ptr;
	}
	printf("NULL\n\n");
}
int main(){
	int choice, value;
	while (1){
		printf("\n1. Push\n2. Pop\n3. Display\n4. Exit\n");
		printf("\nEnter your choice : ");
		scanf("%d", &choice);
		switch (choice){
			case 1:
				printf("\nEnter the value to insert: ");
				scanf("%d", &value);
				push(value);
				break;
			case 2:
				printf("Popped element is :%d\n", pop());
				break;
			case 3:
				display();
				break;
			case 4:
				exit(0);
				break;
			default:
			printf("\nWrong Choice\n");
		}
	}
}