Implement Stack in C Using Array: Push, Pop, Display Operations

A stack is a linear data structure that follows the Last In First Out (LIFO) principle. You can only access or remove the topmost element, just like a stack of plates. In this blog post, you will learn how to implement a stack in C using an array and perform basic operations like push, pop, and display.

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What is a Stack?

A stack is a collection of elements with two main operations:

• Push – Add an element to the top.
• Pop – Remove the top element.

A third operation often used is:

• Display – Show all elements in the stack.

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Stack Implementation in C Using Array

Here’s a complete program in C that implements a stack using an array.

#include <stdio.h>
#define SIZE 100

int stack[SIZE];
int top = -1;

// Function to push an element
void push(int value) {
    if (top == SIZE - 1) {
        printf("Stack Overflow\n");
    } else {
        top++;
        stack[top] = value;
        printf("%d pushed to stack\n", value);
    }
}

// Function to pop an element
void pop() {
    if (top == -1) {
        printf("Stack Underflow\n");
    } else {
        printf("%d popped from stack\n", stack[top]);
        top--;
    }
}

// Function to display the stack
void display() {
    if (top == -1) {
        printf("Stack is empty\n");
    } else {
        printf("Stack elements:\n");
        for (int i = top; i >= 0; i--) {
            printf("%d\n", stack[i]);
        }
    }
}

int main() {
    int choice, value;

    while (1) {
        printf("\n1. Push\n2. Pop\n3. Display\n4. Exit\nEnter your choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                printf("Enter value to push: ");
                scanf("%d", &value);
                push(value);
                break;
            case 2:
                pop();
                break;
            case 3:
                display();
                break;
            case 4:
                return 0;
            default:
                printf("Invalid choice!\n");
        }
    }
}

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Output Example

1. Push
2. Pop
3. Display
4. Exit
Enter your choice: 1
Enter value to push: 10
10 pushed to stack

Enter your choice: 3
Stack elements:
10

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Key Points

• Stack uses LIFO logic.
• Always check for overflow and underflow conditions.
• Arrays make it easy to implement stack but have a fixed size.

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Conclusion

You now understand how to implement a stack in C using array. This includes handling push, pop, and display operations with proper checks for overflow and underflow. Mastering this basic data structure is a stepping stone to learning more complex topics like linked lists, queues, and trees.