Problem
The decorator pattern adds behaviour by wrapping an object in layers. Each layer here changes the price of the layer inside it.
Start from base_price and apply the decorators in order:
discount p: reduce the price by p percent.tax p: increase the price by p percent.shipping a: add a fixed amount a.coupon a: subtract a, but never go below 0.
Implement price_decorators(base_price, decorators).
Input
base_price: The starting price.
decorators: The layers, in the order they wrap the price. Amounts may have decimals.
Output
Return the final price. Answers within 1e-6 are accepted.
Einschränkungen
0 ≤ base_price ≤ 1,000,000
0 ≤ number of decorators ≤ 100; 0 ≤ p ≤ 100, 0 ≤ a ≤ 100,000
Beispiele
Eingabe:
base_price = 100
decorators = ["discount 10", "tax 8", "shipping 5"]
Erwartete Ausgabe:
expected = 102.2Eingabe:
long long base_price = 100;
std::vector<std::string> decorators = {"discount 10", "tax 8", "shipping 5"};
Erwartete Ausgabe:
double expected = 102.2;Eingabe:
long base_price = 100;
string[] decorators = new string[] {"discount 10", "tax 8", "shipping 5"};
Erwartete Ausgabe:
double expected = 102.2;Erläuterung
100 − 10% = 90, plus 8% tax = 97.2, plus 5 shipping = 102.2.
Eingabe:
base_price = 20
decorators = ["coupon 25", "shipping 4"]
Erwartete Ausgabe:
expected = 4.0Eingabe:
long long base_price = 20;
std::vector<std::string> decorators = {"coupon 25", "shipping 4"};
Erwartete Ausgabe:
double expected = 4.0;Eingabe:
long base_price = 20;
string[] decorators = new string[] {"coupon 25", "shipping 4"};
Erwartete Ausgabe:
double expected = 4.0;Erläuterung
The coupon would take the price below zero, so it stops at 0; shipping then makes it 4.
So gehst du vor
Versuch es zuerst allein und öffne dann einen Hinweis nach dem anderen.
Hinweis 1
Apply the layers strictly in the given order.
Hinweis 2
Percentages are taken from the current price, not the base price.
Hinweis 3
A coupon can never push the price below 0.
Erwartete Komplexität
O(number of decorators) time, O(1) extra space
Referenzen
Diese Aufgabe wurde für CodeUtility angepasst. Beachte die oben genannten Vorgaben und Einschränkungen.