Copyright ©
2005 Suradet Jitprapaikulsarn
สงวนลิขสิทธิ์ 2548 สุรเดช จิตประไพกุลศาล
Homework 3 (Due Monday 27 June 2548)
1. Write a function to calculate the cost of shipping according to the
following table. Solution.
|
First
500kg
|
15 ฿ / kg |
| Next 1,000kg |
14 ฿ / kg
|
|
Next 5,00kg
|
13 ฿ / kg
|
|
Next 10,000kg
|
12 ฿ / kg
|
|
Else
|
10 ฿ / kg
|
;----------------------------------------------------------------------------
;
@description calculate the cost of shipping according to the following
table
;
First 500
kg 15
Baht/kg
;
Next 1,000
kg 14
Baht/kg
;
Next 5,000
kg 13
Baht/kg
;
Next 10,000
kg 12
Baht/kg
;
Anything
above 10
Baht/kg
;
@param weight the weight of the shipment
;
@return the cost of shipping
;
@contract shippingCost : number -> number
;
@example (shippingCost 400) = 6000
;
@example (shippingCost 500) = 7500
;
@example (shippingCost 1500) = 21500
;
@example (shippingCost 3000) = 41000
;
@example (shippingCost 6500) = 86500
;
@example (shippingCost 10000) = 128500
;
@example (shippingCost 16500) = 206500
;
@example (shippingCost 30000) = 341500
;----------------------------------------------------------------------------
(define
(shippingCost weight)
(cond
[(<= weight 500) (* 15 weight)]
[(<= weight 1500) (+ (* 14 (- weight 500) ) 7500)]
[(<= weight 6500) (+ (* 13 (- weight 1500) ) 21500)]
[(<= weight 16500) (+ (* 12 (- weight 6500) ) 86500)]
[else (+ (* 10 (- weight 16500) ) 206500)]))
;------
;
Test
;------
"(shippingCost
400) = " (shippingCost 400)
"(shippingCost
500) = " (shippingCost 500)
"(shippingCost
1500) = " (shippingCost 1500)
"(shippingCost
3000) = " (shippingCost 3000)
"(shippingCost
6500) = " (shippingCost 6500)
"(shippingCost
10000) = " (shippingCost 10000)
"(shippingCost
16500) = " (shippingCost 16500)
"(shippingCost
30000) = " (shippingCost 30000)