Bake.java

import java.util.Scanner;

public class Bake {

	// Constants for bag sizes
	static final double[] FLR_SIZES = { 750, 500, 250 };
	static final double[] SUG_SIZES = { 600, 400, 200 };
	static final double[] BUT_SIZES = { 500, 250, 125 };
	static final double[] EGG_SIZES = {  12,  10,   6 };
	
	// Constants for cupcake recipe
	static final double CUP_FLR = 12;
	static final double CUP_SUG = 14;
	static final double CUP_BUT = 4;
	static final double CUP_EGG = 0.1;
	
	// Constants for drizzle cake recipe
	static final double DRZ_FLR = 240;
	static final double DRZ_SUG = 300;
	static final double DRZ_BUT = 80;
	static final double DRZ_EGG = 4.5;
	
	public static void main(String[] args) {
		// Scanner to get console input
		Scanner input = new Scanner(System.in);
		
		// Get quantities of each cake  
		double numCupCakes = -1, numDrzCakes = -1;
		
		// Query the user until they have given positive quantities
		System.out.printf("Please enter a (positive) number of Cupcakes to order:\n");
		while (numCupCakes < 0) {
			numCupCakes = input.nextInt();
		}
		System.out.printf("Please enter a (positive) number of Drizzle Cakes to order:\n");
		while (numDrzCakes < 0) {
			numDrzCakes = input.nextInt();
		}
		
		// Prompt back what the user asked for
		System.out.printf("\nYou have ordered %d Cupcake(s) and %d Drizzle Cake(s).\n", 
							(int) numCupCakes, (int) numDrzCakes);
		
		// Calculate total quantities of each ingredient
		final double flr = (numCupCakes * CUP_FLR) + (numDrzCakes * DRZ_FLR);
		final double sug = (numCupCakes * CUP_SUG) + (numDrzCakes * DRZ_SUG);
		final double but = (numCupCakes * CUP_BUT) + (numDrzCakes * DRZ_BUT);
		final double egg = (numCupCakes * CUP_EGG) + (numDrzCakes * DRZ_EGG);
		
		// Calculate the number and types of bags needed to satisfy the order
		System.out.printf("\nIngredients to dispatch:\n");
		calcBags("Flour",  flr, FLR_SIZES);
		calcBags("Sugar",  sug, SUG_SIZES);
		calcBags("Butter", but, BUT_SIZES);
		calcBags("Eggs",   egg, EGG_SIZES);
	}
	
	public static void calcBags(String name, double amount, double[] sizes) {
		// Start with none of each bag
		int[] num = { 0, 0, 0 };
		
		// Start packing with the largest bags first
		int currentSize = 0;
		
		// Keep packing bags until there's nothing left to pack
		double amountLeft = amount;
		while (amountLeft > 0) {
			
			// Pack the current sized bag
			if ((amountLeft >= sizes[currentSize]) || (currentSize == (sizes.length - 1))) {
				amountLeft -= sizes[currentSize];
				num[currentSize]++;
			}
			else {
				// Otherwise go to the next smallest bag size
				currentSize++;
			}
		}
		
		// Output the result to console
		System.out.printf("%-10s | Requested %-10.0f | Supplied %-10.0f | %-3d Small | %-3d Medium | %-3d Large\n", 
							name, amount, (amount - amountLeft), num[2], num[1], num[0]);
	}
	
}