C program to implement a stack using linked list

#include<stdio.h>
void push();
void pop();
void display();
main()
{
int n;
printf("\tMENU\n1.PUSH\n2.POP\n3.DISPLAY\n4.EXIT\n");
do
{
printf("\nEnter your choice\n");
scanf("%d",&n);
switch(n)
{
case 1:
push();
break;
case 2:
pop();
break;
case 3:
display();
break;
case 4:
break;
default:
printf("Invalid choice\n");
break;
}
}
while(n!=4);
}

typedef struct node
{
int data;
struct node *link;
}n;
n *top=NULL;

void push()
{
int item;
n *temp;
printf("Enter the item\n");
scanf("%d",&item);
temp=(n*)malloc(sizeof(n));
temp->data=item;
temp->link=top;
top=temp;
}

void pop()
{
n *temp;
if(top==NULL)
printf("Stack is empty\n");
else
{
temp=top;
printf("The element deleted = %d\n",temp->data);
free(temp);
top=top->link;
}
}

void display()
{
n *save;
if(top==NULL)
printf("Stack is empty\n");
else
{
save=top;
printf("The elements of the stack are :");
while(save!=NULL)
{
printf("%d\t",save->data);
save=save->link;
}
printf("\nTopmost element = %d\n",top->data);
}
}

C program to implement a stack using array

#include<stdio.h>
main()
{
int a[10]={0},i,top=-1,max=10,n,x;
printf("\n\tMENU\n1.PUSH\n2.POP\n3.DISPLAY\n4.EXIT\n");
do
{
printf("\nEnter your choice\n");
scanf("%d",&n);
switch(n)
{
case 1:
if(top==max-1)
printf("Overflow\n");
else
{
printf("Enter the element\n");
scanf("%d",&x);
a[++top]=x;
}
break;

case 2:
if(top<0)
printf("Underflow\n");
else
printf("The deleted item =%d",a[top--]);
break;

case 3:
if(top<0)
printf("The stack is empty\n");
else
{
printf("The elements of the stack are :");
for(i=0;i<=top;i++)
printf("%d\n",a[i]);
}
break;

case 4:
break;

default:
printf("Invalid choice\n");
break;
}
}
while(n!=4);
}