Week 04 Tutorial Questions

Tutorial Overview:

Part 1: Functions Practice

Tutor Demo! (10 mins)

The parts of a function

return_type function_name(parameters) {
    // function body 

    return value;
}

Your turn! (20 mins)

We have been provided a program which simulates a bubble tea shop and is very similar to last weeks coffee shop activity. All the code for the program is currently in the main function and this task involved you working together to refactor the program to use a series of functions.

// bubble_tea.c
//
// Written by YOUR-NAME (YOUR-ZID) on TODAYS-DATE
//
// This program is a simple bubble tea store used to teach functions

#include <stdio.h>

#define LARGE 'L'
#define REGULAR 'R'
#define ADDED_COST 0.5
#define BASE_TEA 10
#define BASE_TOPPINGS 5
#define BASE_COST 6.5

// enum definitions
enum bubble_tea_type {
    MILK_TEA,
    FRUIT_TEA,
    TARO_MILK,
    MATCHA_LATTE,
};

enum topping_types {
    TAPIOCA_PEARLS,
    JELLY,
    POPPING_PEARLS,
    ALOE_VERA,
};

// struct definitions
struct bubble_tea {
    enum bubble_tea_type type;
	enum topping_types topping;
	int topping_qty;
    char size;
};

struct inventory {
    int tea;
    int toppings;
};

////////////////////////////////////////////////////////////////////////////////
////////////////////////////// FUNCTION PROTOYPES //////////////////////////////
////////////////////////////////////////////////////////////////////////////////

// TODO: Add functions protoypes here

////////////////////////////////////////////////////////////////////////////////
////////////////////////////// MAIN FUCNTION ///////////////////////////////////
////////////////////////////////////////////////////////////////////////////////

int main(void) {
    struct inventory inventory;
    inventory.tea = BASE_TEA;
    inventory.toppings = BASE_TOPPINGS;

    // Take the user's bubble tea order
    struct bubble_tea order;
    int type;

    printf("Enter bubble tea type (0: MILK TEA, 1: FRUIT TEA, 2: TARO MILK, "
            "3: MATCHA LATTE): ");
    scanf("%d", &type);
    if (type == 0) {
        order.type = MILK_TEA;
    } else if (type == 1) {
        order.type = FRUIT_TEA;
    } else if (type == 2) {
        order.type = TARO_MILK;
    } else if (type == 3) {
        order.type = MATCHA_LATTE;
    }

    printf("Enter topping (0: TAPIOCA PEARLS, 1: JELLY, 2: POPPING PEARLS, "
            "3: ALOE VERA): ");
    scanf("%d", &type);
    if (type == 0) {
        order.topping = TAPIOCA_PEARLS;
    } else if (type == 1) {
        order.topping = JELLY;
    } else if (type == 2) {
        order.topping = POPPING_PEARLS;
    } else if (type == 3) {
        order.topping = ALOE_VERA;
    }

    printf("Enter topping qty: ");
    scanf("%d", &order.topping_qty);

    printf("Enter size (L for Large, R for Regular): ");
    scanf(" %c", &order.size);

    // Check available stock and end the program if insufficient stock
    if (inventory.tea - 1 <= 0 ||
        inventory.toppings - order.topping_qty <= 0) {
        printf("Sorry, we cannot fulfill your bubble tea order due to "
                "insufficient stock.\n");
        return 1; 
    }

    // Calculate the cost
    double total_cost = BASE_COST;

    if (order.size == LARGE) {
        total_cost += ADDED_COST;
    }

    if (order.type == MILK_TEA ||
        order.type == TARO_MILK ||
        order.type == MATCHA_LATTE) {
        total_cost += ADDED_COST;
    }

    int count = 0;
    while (count < order.topping_qty) {
        total_cost += ADDED_COST;
        count++;
    }

    // Print the final order and cost
    printf("Order:\n");
    printf("Type: %d\n", order.type);
    printf("Topping Qty: %d\n", order.topping_qty);
    printf("Size: %c\n", order.size);
    printf("Total Cost: %.2lf\n", total_cost);

    // Update the stock after fulfilling the order
    if (order.size == LARGE) {
        inventory.tea -= 2;
    } else {
        inventory.tea -= 1;
    }
            
    inventory.toppings -= order.topping_qty;

    // Step 6: print the remining inventory
    printf("The current inventory is: ");
    printf("Bubble tea(s): %d\n", inventory.tea);
    printf("Topping(s): %d\n", inventory.toppings);


    return 0;
}

////////////////////////////////////////////////////////////////////////////////
///////////////////////////// FUNCTION DEFINITIONS /////////////////////////////
////////////////////////////////////////////////////////////////////////////////

// TODO: Write function definitionds here

Extra Tip: When to Create Your Own Functions?

In the above activity, we have seen functions created for the specific context. However, when you are creating your own functions, if you are unsure what code you should put into functions, here are some example operations that programmers often create functions for:

Part 2: Style (10 mins)

This Kahoot will cover points from the https://cgi.cse.unsw.edu.au/~dp1091/25T1/resources/style_guide.html