stack

//m.d.p stack as array
#include<stdio.h>
#define MAX 5
int top=-1;
int stack[MAX];

void push()
{
    int data;
    if(top==MAX-1)
    {
        printf("\nOVERFLOW\n");
    }
    else
    {
        printf("enter the value:");
        scanf("%d",&data);
        top++;
        stack[top]=data;
        printf("\nelement pushed successfully\n");
    }
}

void pop()
{
    if(top==-1)
    {
        printf("\nUNDERFLOW\n");
    }
    else
    {
        printf("popped element: %d\n",stack[top]);
        top--;
        printf("\nelement popped successfully\n");
    }

}

void display()
{
    if(top==-1)
    {
        printf("\nstack is empty\n");
    }
    else
    {
        printf("elements:\n");
        for(int i=top;i>=0;i--)
        {
            printf("%d\n",stack[i]);
        }
    }
}

int main()
{
    int ch;
    while(ch!=4)
    {
        printf("\npress 1 for push operation\n");
        printf("press 2 for pop operation \n");
        printf("press 3 for display \n");
        printf("press 4 for exit \n");
        printf("enter your choice:");
        scanf("%d",&ch);
        switch(ch)
        {
            case 1:
            push();
            break;
            case 2:
            pop();
            break;
            case 3:
            display();
            break;
            case 4:
            printf("\nEXIT \n");
            break;
            default:
            printf("\nINVALID INPUT\n");
            break;
        }
    }
    return 0;
}