Pushing, Popping and Displaying a Stack

#include <stdio.h>
#include <stdlib.h> //required for using malloc() at line 19
int size, count; //Global variables are initialized to 0
void push(int stack[], int value){
    stack[count++] = value;
}
void pop(int stack[]){
    count--;
}
void display(int stack[]){
    if(count == 0) printf("\nThe stack is empty.");
    else for(int i = count-1; i >= 0; i--) printf("%d\n", stack[i]);
    if(count == size) printf("\nThe stack is full.");
}
int main(){
    int choice, n;
    printf("\nEnter the size of the stack: ");
    scanf("%d", &size);
    int *stack = (int*) malloc(sizeof(int) * size); //A better alternative to int stack[100];
    while(1){
        display(stack);
        printf("\n1.Push 2.Pop 3.Exit: ");
        scanf("%d", &choice);
        switch(choice){
            case 1: if(count != size){
                        printf("Enter the number to push: ");
                        scanf("%d", &n);
                        push(stack, n);
                    } else printf("\nError: Overflow\n");
                    break;
            case 2: if(count != 0) pop(stack);
                    else printf("\nError: Underflow.\n");
                    break;
            case 3: return 0;
        }
    }
}