EXP2a.txt

#include <stdio.h>
#include <stdlib.h>

#define MAX 5

// Stack structure
static int stack[MAX];
int top = -1;

// Function to push an element onto the stack
void push(int x) {
    if (top < MAX - 1) {
        stack[++top] = x;
        printf("\n%d pushed to stack\n", x);
    } else {
        printf("\nStack Overflow\n");
    }
}

// Function to pop an element from the stack
int pop() {
    if (top >= 0) {
        return stack[top--];
    } else {
        printf("\nStack Underflow\n");
        return -1; // Return an invalid value
    }
}

// Function to view the elements in the stack
void view() {
    if (top < 0) {
        printf("\nStack Empty\n");
    } else {
        printf("\nStack elements (top --> bottom):\n");
        for (int i = top; i >= 0; i--) {
            printf("%d ", stack[i]);
        }
        printf("\n");
    }
}

// Main function to drive the stack operations
int main() {
    int choice = 0, val;

    while (choice != 4) {
        printf("\nSTACK OPERATIONS\n");
        printf("1. PUSH\n");
        printf("2. POP\n");
        printf("3. VIEW\n");
        printf("4. QUIT\n");
        printf("Enter Choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                printf("Enter Stack element: ");
                scanf("%d", &val);
                push(val);
                break;
            case 2:
                val = pop();
                if (val != -1) {
                    printf("Popped element is %d\n", val);
                }
                break;
            case 3:
                view();
                break;
            case 4:
                printf("Exiting...\n");
                exit(0);
            default:
                printf("\nInvalid Choice\n");
        }
    }
    return 0;
}