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Stack Implementation in C

yashdesai profile image Yash Desai Updated on ・2 min read

We need these header files...

#include <stdio.h>
#include <conio.h>
#include <stdlib.h>
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Let's define some constants...

// constants
#define MAX 5              // Max capacity of a stack
#define ERR "\x1B[31m"     // Error Color
#define SUCCESS "\x1B[32m" // Success Color
#define RESET "\033[0m"    // Reset Color
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Constants defined in above lines of code such as ERR,SUCCESS and RESET will be used to color the text of printf(). MAX defines the maximum capacity of the stack

Now we'll declare a stack...

//declaration of stack
typedef struct stack
{
    int entry[MAX];
    int top;
} stack;
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Initialization of stack

//stack initialization
void init(stack *sptr)
{
    sptr->top = 0;
}
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A function to check if Stack is empty...

//checking stack is empty or not.
int isEmpty(stack *sptr)
{
    if (sptr->top == 0)
        return (1);
    else
        return (0);
}
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A function to check if stack is overflowed...

//checking stack is full or not.
int isFull(stack *sptr)
{
    if (sptr->top == MAX)
        return (1);
    else
        return (0);
}
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A function to push/insert a new element into the stack...

//Inserting element into stack
void push(stack *sptr)
{
    int item;
    if (isFull(sptr))
        printf(ERR "\tSTACK IS FULL" RESET);
    else
    {
        printf("\n\tEnter the element: ");
        scanf("%d", &item);
        sptr->entry[sptr->top] = item;
        sptr->top++;
    }
}
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A function to pop/remove elements from the stack...

//Deleting element from the stack
void pop(stack *sptr)
{
    int item;

    if (isEmpty(sptr))
        printf(ERR "\tSTACK IS EMPTY" RESET);
    else
    {
        sptr->top--;
        item = (sptr->entry[sptr->top]);
        printf(SUCCESS "\t%d HAS BEEN REMOVED" RESET, item);
    }
}
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A function to traverse though the stack or print all the elements of the stack

//Traversing the elements of stack
void traverse(stack *sptr)
{
    if (isEmpty(sptr))
        printf(ERR "\tSTACK IS EMPTY" RESET);
    else
    {
        int i;

        for (i = sptr->top - 1; i >= 0; i--)
            printf("\t-> %d\n", sptr->entry[i]);
    }
}
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And finally the main() function...

int main()
{
    stack s;
    int choice;

    init(&s);

    do
    {
        printf("\n 1. PUSH");
        printf("\n 2. POP");
        printf("\n 3. TRAVERSE");
        printf("\n 4. EXIT");
        printf("\n\nEnter the choice: ");
        scanf(" %d", &choice);
        switch (choice)
        {
        case 1:
            push(&s);
            break;
        case 2:
            pop(&s);
            break;
        case 3:
            traverse(&s);
            break;
        case 4:
            exit(0);
            break;
        default:
            printf(ERR "\tWRONG CHOICE" RESET);
        }
    } while (1);

    return 0;
    getch();
}
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Output

Alt Text

Alt Text

Pushed 5 elements to the stack. (max capacity=5)

Alt Text

Alt Text

Removed two elements from the stack

Alt Text

Removed all elements until the stack is empty

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Enjoy :)

Discussion (2)

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clavinjune profile image
Clavin June

You can do this btw

//checking stack is empty or not.
int isEmpty(stack *sptr)
{
    return !sptr->top;
}
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I think you shouldn't do traverse in stack.

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yashdesai profile image
Yash Desai Author

Yes, I do agree with you. Thanks for correction!