CS 100: Lecture L24
April 22
public class MailOrder extends Retailer
{
/* Inherits variables
protected int nStores; // Number of stores.
protected int nItems; // Number of items.
protected int[][] price; // Price array: price[i][j] is the price (in dollars) of item j in store i.
protected int[][] inv; // Inventory array: inv[i][j] is the inventory of item j in store i.
*/
protected double[] weight; // Weight array. weight[j] is the weight(kg) of item j, j=0,...,nItems-1.
protected double[] location; // Store locations. The stores are located on the x-axis and for
// i = 0,1,...,nStores-1, location[i] is its x-coordinate (in km).
protected double rate; // Shipping rate. The cost to ship one kg of merchandise one km
public MailOrder(int[][] P, int[][] I, double[] w, double[] x, double r)
// P is the price array and I is the inventory array. They are the same size. The number
// of stores equals the number of rows and the number of retail items equals the number of columns.
// w is the weight array and x is the location array.
//
{
super(P,I);
location = copy(x);
weight = copy(w);
rate = r;
}
public static double[] copy(double[] a)
{
int n = a.length;
double[] b = new double[n];
for(int i=0;i< n;i++)
b[i] = a[i];
return b;
}
// i satisfies 0 < = i < nStores.
// PO represents a purchase order. It has length nItems and P0[j] is the
// quantity of item j that the customer wishes to buy.
// Yields the cost of processing the purchase order at store i.
public int iCost(int i, int[] PO, double x)
{
// Find the value of the merchandise.
int value = iCost(i,PO);
// Determine the total shipping cost.
double shippingWeight = 0;
for(int j=0;j< nItems;j++)
shippingWeight = shippingWeight + weight[j]*PO[j];
int shippingCost = (int)(rate*shippingWeight*Math.abs(x-location[i]));
return value + shippingCost;
}
// PO represents a purchase order. It has length nItems and P0[j] is the
// quantity of item j that the customer wishes to buy.
// If no store can process the purchase order then an appropriate message is
// printed and each store increases its inventory just enough so that it can
// process the PO "the next time".
// Otherwise, the index of the store that can most cheaply fill the PO is printed
// along with the minimum cost. The store that processes the order has its inventory
// depleted accordingly.
public void processPO(int[] PO, double x)
{
int i = 0;
while (i< nStores && !iCanDo(i,PO))
i++;
if (i==nStores)
{
// No store has sufficient inventory.
System.out.println("No single store can process this order at this time.");
updateInv(PO);
}
else
{
// Find the store that can most cheaply fill the PO.
// NOTE: iCost is overloaded. Java can tell by the signature to use the version
// above and not the version in the parent class Retailer.
int minCost = iCost(i,PO,x);
int bestStore = i;
for (int s=i+1;s< nStores;s++)
if (iCanDo(s,PO) && iCost(s,PO,x)< minCost)
{
bestStore = s;
minCost = iCost(s,PO,x);
}
System.out.println("Price at store " + bestStore + " is " + minCost);
updateInv(bestStore,PO);
}
}
}
import java.io.*;
public class ShowMailOrder
{
public static void main(String args[])
{
TokenReader in = new TokenReader(System.in);
// A sample price array.
int[][] eg_P = { { 32 , 20 , 22 , 12 , 19 , 17 , 31 , 12} ,
{ 34 , 22 , 25 , 10 , 13 , 19 , 33 , 15} ,
{ 34 , 21 , 24 , 13 , 17 , 17 , 34 , 12} };
// A sample inventory array.
int[][] eg_I = { { 10 , 20 , 60 , 10 , 40 , 70 , 20 , 10} ,
{ 90 , 40 , 80 , 50 , 30 , 40 , 80 , 90} ,
{ 30 , 60 , 40 , 30 , 90 , 70 , 30 , 80} };
// A sample weight array
double[] eg_w = { .10 , .20 , .05 , .15 , .10 , .08 , .07 , .30};
// A sample location array
double[] eg_x = {30.2 , 7.6 , 48.9};
double eg_r = 2.0;
// Build a mail order business and process three customers located at x = 10, 30, and 50.
MailOrder TallMart = new MailOrder(eg_P,eg_I,eg_w, eg_x, eg_r);
TallMart.showInv();
int[] PO1 = {10,10,10,10,10,10,10,10}; TallMart.processPO(PO1,10); TallMart.showInv();
int[] PO2 = {20,20,20,20,20,20,20,20}; TallMart.processPO(PO2,30); TallMart.showInv();
int[] PO3 = {100,0,0,0,0,0,0,0}; TallMart.processPO(PO3,50); TallMart.showInv();
in.waitUntilEnter();
}
}
/* Output:
10 20 60 10 40 70 20 10
90 40 80 50 30 40 80 90
30 60 40 30 90 70 30 80
Price at store 1 is 1760
10 20 60 10 40 70 20 10
80 30 70 40 20 30 70 80
30 60 40 30 90 70 30 80
Price at store 2 is 4233
10 20 60 10 40 70 20 10
80 30 70 40 20 30 70 80
10 40 20 10 70 50 10 60
No single store can process this order at this time.
100 20 60 10 40 70 20 10
100 30 70 40 20 30 70 80
100 40 20 10 70 50 10 60
*/