Implement stack and perform push, and pop operations

C Program

#include <stdio.h>
#include <conio.h>
#define MAXSIZE 5
struct stack            
/* Structure definition for stack */ {
	int stk[MAXSIZE];
	int top;
};
typedef struct stack STACK;
STACK s;
/* Function declaration/Prototype*/
void push (void);
int  pop(void);
void display (void);
void main () {
	int choice;
	int option = 1;
	clrscr ();
	s.top = -1;
	printf ("STACK OPERATION\n");
	while (option) {
		printf ("------------------------------------------\n");
		printf ("  	1	-->	PUSH	           \n");
		printf ("  	2	-->	POP	           \n");
		printf ("  	3	-->	DISPLAY	           \n");
		printf ("  	4	-->	EXIT		   \n");
		printf ("------------------------------------------\n");
		printf ("Enter your choice\n");
		scanf	("%d", &choice);
		switch (choice) {
			case 1: push();
			break;
			case 2:	pop();
			break;
			case 3:	display();
			break;
			case 4:	return;
		}
		fflush (stdin);
		printf ("Do you want to continue(Type 0 or 1)?\n");
		scanf	("%d", &option);
	}
}
/*Function to add an element to the stack*/
void push () {
	int num;
	if (s.top == (MAXSIZE - 1)) {
		printf ("Stack is Full\n");
		return;
	} else {
		printf ("Enter the element to be pushed\n");
		scanf ("%d", &num);
		s.top = s.top + 1;
		s.stk[s.top] = num;
	}
	return;
}
/*Function to delete an element from the stack*/
int pop () {
	int num;
	if (s.top == - 1) {
		printf ("Stack is Empty\n");
		return (s.top);
	} else {
		num = s.stk[s.top];
		printf ("poped element is = %d\n", s.stk[s.top]);
		s.top = s.top - 1;
	}
	return(num);
}
/*Function to display the status of the stack*/
void display () {
	int i;
	if (s.top == -1) {
		printf ("Stack is empty\n");
		return;
	} else {
		printf ("\nThe status of the stack is\n");
		for (i = s.top; i >= 0; i--) {
			printf ("%d\n", s.stk[i]);
		}
	}
	printf ("\n");
}

Output

STACK OPERATION
------------------------------------------
	1       -->     PUSH
        2       -->     POP
	3       -->     DISPLAY
        4       -->     EXIT
------------------------------------------
Enter your choice
1
Enter the element to be pushed
23
Do you want to continue(Type 0 or 1)?
1
------------------------------------------
	1       -->     PUSH
        2       -->     POP
	3       -->     DISPLAY
        4       -->     EXIT
------------------------------------------
Enter your choice
1
Enter the element to be pushed
45
Do you want to continue(Type 0 or 1)?
1
------------------------------------------
		  1       -->     PUSH
        2       -->     POP
		  3       -->     DISPLAY
        4       -->     EXIT
------------------------------------------
Enter your choice
1
Enter the element to be pushed
78
Do you want to continue(Type 0 or 1)?
1
------------------------------------------
        1       -->     PUSH
        2       -->     POP
	3       -->     DISPLAY
        4       -->     EXIT
------------------------------------------
Enter your choice
3

The status of the stack is
78
45
23

Do you want to continue(Type 0 or 1)?
1
------------------------------------------
        1       -->     PUSH
	2       -->     POP
        3       -->     DISPLAY
        4       -->     EXIT
------------------------------------------
Enter your choice
2
poped element is = 78
Do you want to continue(Type 0 or 1)?
1
------------------------------------------
        1       -->     PUSH
	2       -->     POP
        3       -->     DISPLAY
        4       -->     EXIT
------------------------------------------
Enter your choice
3

The status of the stack is
45
23

Do you want to continue(Type 0 or 1)?
0