Modifying a stack program to accept characters

[random123salad]

Hello, I am working on an assignment where we take a stack program and make it so it accepts characters. Then I need to add a main function that asks the user to input a series of braces or parenthesis and indicate whether or not they're properly nested. My program I need to modify is as follows: I do know a lot of the basics such as printf, return 0; and whatever, but these stacks are really messing with me. Any ideas or help on the subject?

#include <stdbool.h>
#define STACK_SIZE 100


int contents[STACK_SIZE];
int top = 0;


void make_empty(void)
{
top = 0;
}


bool is_empty(void)


{
    return top == 0;
}
bool is_full(void)
{
    return top == STACK_SIZE;
}


void push(int i)
{
    if (is_full())
            stack_overflow();
    else
        contents[top++] = i;
}


int pop(void)
{
    if (is_empty())
        stack_underflow();
    else
        return contents[--top];
}

[laserlight]

For starters, you should declare a stack struct that looks like this:

struct stack
{
    char contents[STACK_SIZE];
    int top;
};

Then for each of the stack functions, add a new first parameter of type struct stack * if it modifies the stack, or const struct stack * otherwise. Of course, you need to change the code to use this parameter instead of global variables.

This way, if your teacher asks you to have two stacks at the same time in the same program, it can be done.

Besides this, you also need to change the parameter of push and return value of pop to be of type char. Once you do these changes, you would have the code for stacks of char, and so you can start writing the main function.