Vending Machine Program

//
//  main.c
//  vendingmachine
//
//  This program simulates a vending machine.
//
//  Created by Robert Doobay on 1/24/17.
//  Copyright © 2017 Robert Doobay. All rights reserved.
//

#include <stdio.h>

int main()
{

    int coin = 1;   // Set to 1 to allow input cash loop to begin
    int choice = 4; // Set to 4 to allow input menu loop to begin
    int cash = 0;

    //  Welcome Statements
    printf("Welcome to Vending Machine 1.0\n");
    printf("Designed by Robert Doobay\n\n");
    printf("Please enter coins by entering the value of each coin.\n");
    printf("Coin values can be either 5, 10, or 25.\n");

    //  Input Cash Loop
    while (coin != 0)
    {
        //  Queries input from user
        printf("Insert Coins:");

        //  Validates input from user
            // Checks if input is numeric
        if (scanf("%d", &coin) != 1) printf("This is not a number, please try again.\n");
            //  Checks if input is a valid coin value
        else if (coin == 5 || coin == 10 || coin == 25 || coin == 0) cash+= coin;
            //  Throws error if illegal numeric value is entered
        else printf("Illegal coin value entered, please try again.\n");

        // Flushes input buffer
        while (getchar() != '\n'){}
    }


    //  Thanks user and displays cash entered
    printf("\nCoins accepted, thank you.\n");
    if (cash%100 != 0) printf("Total Cash: $%d.%d\n\n", cash/100, cash%100);
    else printf("Total Cash: $%d.00\n\n", cash/100);

    //  Input Menu Loop
    printf("Please enter the corresponding number of the desired item from the following menu:\n");
    printf("1: Coffee   25 cents\n2: Tea      15 cents\n0: Return Cash\n\n");
    printf("Choice: ");

    while (choice != (0 | 1 | 2))
    {
        //  Validates Input
        if (scanf("%d", &choice) != 1) printf("This is not a number. Please try again.\n");

        //  Serves Coffee, Tea, Returns Cash, or throws error if illegal input is entered.
        else switch (choice)
        {
            case 1:
                cash-= 25;
                printf("Serving Coffee...\nYour change is $%d.%d\n", cash/100, cash%100);
                break;
            case 2:
                cash-= 15;
                printf("Serving Tea...\nYour change is $%d.%d\n", cash/100, cash%100);
                break;
            case 0:
                cash = 0;
                printf("Your cash has been returned.\n");
                break;
            default:
                printf("Illegal value entered, please try again.\n");
                // Flushes input buffer
                while (getchar() != '\n'){}
                printf("Choice: ");
                break;
        }

    }


    return 0;
}