Implementation stack using switch case and while loop using C language - c

Question

I have written the following program to implement PUSH and POP operations in the stack in such a way that the program will execute till the user choose to exit. Users can perform PUSH, POP, and display the stack in a single execution. But after the execution of the program when I choose the option (1/2/3/4) in console windows, I get executed with an infinite output. So, what modification should I done in the following program:
#include<stdio.h>
#include<stdlib.h>
int maxsize, item;
int top = -1;
int ch;
int is_stack_empty ();
int is_stack_full ();
int push (int[]);
int pop (int[]);
int display (int[]);
int main()
{
printf("Enter the size of stack: ");
scanf("%d", &maxsize);
int stack[maxsize];
printf("\n 1. PUSH");
printf("\n 2. POP");
printf("\n 3. Display");
printf("\n 4. Exit");
printf("\nEnter your choice: ");
scanf("%d", &ch);
while (1)
{
switch (ch)
{
case 1:
push (stack);
break;
case 2:
pop (stack);
break;
case 3:
display (stack);
break;
case 4:
exit(1);
break;
default:
printf("\nError! please select correct option");
}
}
return 0;
}
int display (int s[])
{
printf("\nThe created stack is :\n");
for (int i = 0; i < top; i++)
{
printf("%d\n", s[i]);
}
}
int is_stack_empty ()
{
if (top == -1)
return 1;
else
return 0;
}
int is_stack_full ()
{
if (top == maxsize-1)
return 1;
else
return 0;
}
int push (int s[])
{
if(!is_stack_full())
{
printf("\nEnter the element of STACK[%d]: ", top+1);
scanf("%d", &item);
top = top + 1;
s[top] = item;
}
else
printf("\nError: Overflow! Stack is full! Couldn't perform PUSH operation.");
}
int pop (int s[])
{
if(!is_stack_empty())
{
printf("\nPopped element is %d", s[top]);
top = top - 1;
}
else
printf("\nError: Underflow! Stack is empty! Couldn't perform POP operation.");
}

Answer 1

The program read the choice from users outside the while loop and hence program reads ch value once. Therefore, the switch statement checks only one ch value. The program should read ch value inside the while loop.
while (1)
{
printf("\nEnter your choice: ");
scanf("%d", &ch);
switch (ch)
{
case 1:
push (stack);
break;
case 2:
pop (stack);
break;
case 3:
display (stack);
break;
case 4:
exit(1);
break;
default:
printf("\nError! please select correct option");
}
}