c program to implement a stack using an array

1#include<stdio.h>
2int stack[100],choice,n,top,x,i;
3void push(void);
4void pop(void);
5void display(void);
6int main()
7{
8    //clrscr();
9    top=-1;
10    printf("\n Enter the size of STACK[MAX=100]:");
11    scanf("%d",&n);
12    printf("\n\t STACK OPERATIONS USING ARRAY");
13    printf("\n\t--------------------------------");
14    printf("\n\t 1.PUSH\n\t 2.POP\n\t 3.DISPLAY\n\t 4.EXIT");
15    do
16    {
17        printf("\n Enter the Choice:");
18        scanf("%d",&choice);
19        switch(choice)
20        {
21            case 1:
22            {
23                push();
24                break;
25            }
26            case 2:
27            {
28                pop();
29                break;
30            }
31            case 3:
32            {
33                display();
34                break;
35            }
36            case 4:
37            {
38                printf("\n\t EXIT POINT ");
39                break;
40            }
41            default:
42            {
43                printf ("\n\t Please Enter a Valid Choice(1/2/3/4)");
44            }
45                
46        }
47    }
48    while(choice!=4);
49    return 0;
50}
51void push()
52{
53    if(top>=n-1)
54    {
55        printf("\n\tSTACK is over flow");
56        
57    }
58    else
59    {
60        printf(" Enter a value to be pushed:");
61        scanf("%d",&x);
62        top++;
63        stack[top]=x;
64    }
65}
66void pop()
67{
68    if(top<=-1)
69    {
70        printf("\n\t Stack is under flow");
71    }
72    else
73    {
74        printf("\n\t The popped elements is %d",stack[top]);
75        top--;
76    }
77}
78void display()
79{
80    if(top>=0)
81    {
82        printf("\n The elements in STACK \n");
83        for(i=top; i>=0; i--)
84            printf("\n%d",stack[i]);
85        printf("\n Press Next Choice");
86    }
87    else
88    {
89        printf("\n The STACK is empty");
90    }
91   
92}
93