C Simple Stack

Header File

/*
 -------------------------------------------------------
 stack_simple.h
 Simple array-based version of the Stack ADT.
 -------------------------------------------------------
 Author:       David Brown
 ID:           987654321
 Email:        dbrown@wlu.ca
 Version:      2017-03-28
 -------------------------------------------------------
 */
#ifndef STACK_SIMPLE_H_
#define STACK_SIMPLE_H_

// Includes
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

// Structures
/**
 * Default stack size.
 */
#define STACK_INIT 8

/**
 * Stack structure.
 */
typedef struct {
    int values[STACK_INIT]; ///< Array of data values.
    int top; ///< index of top element of the stack.
} stack;

// Prototypes

/**
 * Initializes a stack structure.
 * @param s the stack to initialize.
 */
void stack_initialize(stack *s);

/**
 * Destroys a stack.
 * @param s pointer to a stack.
 */
void stack_destroy(stack *s);

/**
 * Determines if a stack is empty.
 * @param s pointer to a stack.
 * @return 1 if the stack is empty, 0 otherwise.
 */
int stack_empty(const stack *s);

/**
 * Determines if a stack is full.
 * @param s pointer to a stack.
 * @return 1 if the stack is full, 0 otherwise.
 */
int stack_full(const stack *s);

/**
 * Pushes a value onto a stack. Terminates if stack is full.
 * @param s pointer to a stack.
 * @param d the data to push.
 */
void stack_push(stack *s, int d);

/**
 * Returns the value on the top of a stack, the stack is unchanged.
 * Terminates if stack is empty.
 * @param s pointer to a stack.
 * @return the value on the top of the stack.
 */
int stack_peek(const stack *s);

/**
 * Returns and removes the value on the top of a stack.
 * Terminates if stack is empty.
 * @param s pointer to a stack.
 * @return the value on the top of the stack.
 */
int stack_pop(stack *s);

/**
 * Prints the elements in a stack from top to bottom.
 * (For testing only).
 * @param s pointer to a stack.
 */
void stack_display(const stack *s);

#endif /* STACK_SIMPLE_H_ */

Source Code (.c)

/*
 -------------------------------------------------------
 stack_simple.c
 Simple array-based version of the Stack ADT.
 -------------------------------------------------------
 Author:       David Brown
 ID:           987654321
 Email:        dbrown@wlu.ca
 Version:      2017-04-25
 -------------------------------------------------------
 */

// Includes
#include "stack_simple.h"

// Functions

void stack_initialize(stack *s) {
    s->top = -1;
    return;
}

void stack_destroy(stack *s) {
    s->top = -1;
    return;
}

int stack_empty(const stack *s) {
    return s->top == -1;
}

int stack_full(const stack *s) {
    return s->top == (STACK_INIT - 1);
}

void stack_push(stack *s, int v) {
    // Cannot push onto a full stack.
    assert(s->top < (STACK_INIT - 1));

    // Add the new data to the values array.
    s->top++;
    s->values[s->top] = v;
    return;
}

int stack_peek(const stack *s) {
    // Cannot peek on an empty stack.
    assert(s->top != -1);

    return s->values[s->top];
}

int stack_pop(stack *s) {
    // Cannot pop on an empty stack.
    assert(s->top != -1);

    int v = s->values[s->top];
    s->top--;
    return v;
}

void stack_display(const stack *s) {
    int i = s->top;

    if (i >= 0) {
        while (i > 0) {
            printf("%d, ", s->values[i]);
            i--;
        }
        printf("%d", s->values[0]);
    }
    printf("\n");
}

Using the Stack

#include "stack_simple.h"

int main(int argc, char *argv[]) {
    int i;
    stack s;

    stack_initialize(&s);

    for (i = 0; i < STACK_INIT; i++) {
        stack_push(&s, i);
    }
    stack_display(&s);
    stack_destroy(&s);
    return 0;
}