Daily Challenge #187 - Most Sales

dev.to staff Feb 14 ・1 min read

#challenge

Daily Challenge (207 Part Series)

You work in the best consumer electronics company around. Your boss asked you to find out which products generate the most revenue.

You'll be given lists of products, amounts, and prices. Given these three lists of same length, return the product name(s) with the highest revenue (amount * price). If multiple products have the same revenue, order them according to their original positions.

Example

products: ["Computer", "Cell Phones", "Vacuum Cleaner"]
amounts: [3, 24, 8]
prices: [199, 299, 399]

return: Cell Phones

Test

products: ["Cell Phones", "Vacuum Cleaner", "Computer", "Autos", "Gold", "Fishing Rods", "Lego", " Speakers"]
amounts: [0, 12, 24, 17, 19, 23, 120, 8]
prices: [9, 24, 29, 31, 51, 8, 120, 14]

This challenge comes from JakobPri on CodeWars. Thank you to CodeWars, who has licensed redistribution of this challenge under the 2-Clause BSD License!

Want to propose a challenge idea for a future post? Email yo+challenge@dev.to with your suggestions!

Daily Challenge (207 Part Series)

DISCUSS (10)

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SavagePixie

Feb 14

Elixir

def get_max_revenue(products, amounts, prices) do
  list = Enum.zip([ products, amounts, prices ])
    |> Enum.map(fn { product, amount, price } -> { product, amount * price } end)
    |> Enum.sort(fn { _, r1 }, { _, r2 } -> r1 >= r2 end)
  first = list
    |> List.first
    |> (fn { _, revenue } -> revenue end).()
  Enum.take_while(list, fn { _, revenue } -> revenue == first end)
    |> Enum.map(fn { product, _ } -> product end)
end

Avalander

Feb 14

Scala

object MostSales {
  private implicit val order = Ordering.Int.reverse

  private val total = (x: ((Int, Int), String)) => x match {
    case ((a, p), n) => (n, a * p)
  }

  def findHighest (names: Seq[String], amounts: Seq[Int], prices: Seq[Int]): Seq[String] = {
    val sorted = amounts zip prices zip names map total sortBy (_._2)
    val result = sorted takeWhile (_._2 == sorted.head._2)
    result map (_._1)
  }
}

And some tests

import org.scalatest._

class MostSalesTest extends FunSuite {
  import MostSales._

  test("Case 1") {
    val products = List("Computer", "Cell Phones", "Vacuum Cleaner")
    val amounts = List(3, 24, 8)
    val prices = List(199, 299, 399)

    val result = findHighest(products, amounts, prices)
    assert(result == List("Cell Phones"))
  }

  test("Case 2") {
    val products = List("Cell Phones", "Vacuum Cleaner", "Computer", "Autos", "Gold", "Fishing Rods", "Lego", " Speakers")
    val amounts = List(0, 12, 24, 17, 19, 23, 120, 8)
    val prices = List(9, 24, 29, 31, 51, 8, 120, 14)

    val result = findHighest(products, amounts, prices)
    assert(result == List("Lego"))
  }

  test("Returns multiple results") {
    val products = List("Computer", "Cell Phones", "Vacuum Cleaner")
    val amounts = List(3, 2, 6)
    val prices = List(200, 299, 100)

    val result = findHighest(products, amounts, prices)
    assert(result == List("Computer", "Vacuum Cleaner"))
  }
}

Avalander

Feb 14

Haskell

module MostSales where

import Data.List (groupBy, head, zip3, sortBy)


findHighest :: [String] -> [Int] -> [Int] -> [String]
findHighest a b c =
    ((map fst) . head . (groupBy value) . (sortBy compare') . (map total)) $ (zip3 a b c)
    where
        total (n, a, b)        = (n, a * b)
        value (_, x)           = ((==) x . snd)
        compare' (_, a) (_, b) = compare b a

Rohit Prasad

Feb 15

Python

for i in range(len(prices)):
        prices[i] = int(amounts[i])*int(prices[i])

j = max(prices)

for i in range(len(prices)):
        if prices[i] == j:
                print(products[i])

Vidit Sarkar

Feb 14

Here is C++ solution

vector<string> highestRevenue(vector<string> products, vector<int> amounts, vector<int> prices){
    vector<int> revenue; // holds the revenue of all products
    for(int i=0; i<amounts.size();i++){
        revenue.push_back(amounts[i]*prices[i]);
    }

    int max_revenue = *max_element(revenue.begin(),revenue.end()); // maximum revenue
    if(max_revenue == 0)
        return vector<string>(); // if maximum revenue is zero then there is no need to return any product

    vector<string> highestRevProducts; // vector storing the products with maximum revenue
    for(int i=0;i<revenue.size();i++)
        if(revenue[i] == max_revenue)
            highestRevProducts.push_back(products[i]);

    return highestRevProducts;
}

Sabin Pandelovitch

Feb 15

Javascript - Reduce method

const products = [
  "Cell Phones",
  "Vacuum Cleaner",
  "Computer",
  "Autos",
  "Gold",
  "Fishing Rods",
  "Lego",
  " Speakers"
];
const amounts = [0, 12, 24, 17, 19, 23, 120, 8];
const prices = [9, 24, 29, 31, 51, 8, 120, 14];

const { productName } = products.reduce(
  (acc, val, i) =>
    amounts[i] * prices[i] > acc.value
      ? {
          productName: val,
          value: amounts[i] * prices[i]
        }
      : acc,
  { productName: "", value: 0 }
);

console.log(productName);

Michael Kohl

Feb 15

OCaml, with Core as stdlib:

let highestSales products amounts prices =
  List.map3_exn products amounts prices (fun prod a p -> prod, a * p) 
  |> List.max_elt ~compare:(fun (_, p1) (_, p2) -> Int.compare p1 p2)
  |> Option.map ~f:fst

This will return None in case all inputs lists are empty, but raise an exception in case they aren't of equal length. That's easy to fix though, as Core defines an appropriate result type for pattern matching against:

let highestSales products amounts prices =
  List.map3 products amounts prices (fun prod a p -> (prod, a * p))
  |> function
  | List.Or_unequal_lengths.Ok l ->
      List.max_elt l ~compare:(fun (_, p1) (_, p2) -> Int.compare p1 p2)
      |> Option.map ~f:fst
  | Unequal_lengths ->
      None

Andrei McMillan

Feb 16

python

def most_sales(product_list, amount_list, price_list):
    if len(product_list) == len(amount_list) == len(price_list):

        revenue_list = []
        top_revenue = []

        for i, n in enumerate(product_list):
            revenue_list.append(amount_list[i] * price_list[i])

        max_val = max(revenue_list)

        for index, value in enumerate(revenue_list):
            if value == max_val:
                top_revenue.append(str(product_list[index]) + ' - ' + '${:,.2f}'.format(value))

        print '\n'.join(top_revenue)
        print '\n' + ('-' * 20) + '\n'
    else:
        print('invalid entries')


most_sales(
    ["Computer", "Cell Phones", "Vacuum Cleaner"],
    [3, 24, 8],
    [199, 299, 399]
)
# Cell Phones - $7,176.00

most_sales(
    ["Cell Phones", "Vacuum Cleaner", "Computer", "Autos", "Gold", "Fishing Rods", "Lego", " Speakers"],
    [0, 12, 24, 17, 19, 23, 120, 8],
    [9, 24, 29, 31, 51, 8, 120, 14]
)
# Lego - $14,400.00

most_sales(
    ["Cell Phones", "Vacuum Cleaner", "Computer", "Autos", "Gold", "Fishing Rods", "Lego", " Speakers"],
    [120, 12, 24, 17, 19, 23, 120, 8],
    [120, 24, 29, 31, 51, 8, 120, 14]
)
# Cell Phones - $14,400.00
# Lego - $14,400.00

Craig McIlwrath

Feb 14

Haskell:

maximumsBy :: Ord b => (a -> b) -> [a] -> [a]
maximumsBy f = foldr g [] 
  where g x [] = [x]
        g x ys = case f x `compare` f (head ys) of
                   LT -> ys
                   EQ -> x : ys
                   GT -> [x]

bestSeller :: (Ord b, Num b) => [a] -> [b] -> [b] -> [a] 
bestSeller ns qs ps = map fst $ maximumsBy snd $
                      zip ns $ zipWith (*) qs ps

divyansh-pratap

Feb 15

include

int main()
{
int i , a , j , revenue;
char A[15][30];
int B[30];
int C[30];
printf("enter the number of inputs you want to enter :");
scanf("%d" , &a);
printf("enter the name of the items :-\n");
for(i=-1;i<a;i++)
{

    gets(A[i]);

}

for(i=0;i<a;i++)
{
    printf("enter the price of %dth element :\n",i+1);
    scanf("%d" , &B[i]);
}
for(i=0;i<a;i++)
{
    printf("\nenter the quantity of %dth element :\n" , i+1);
    scanf("%d" , &C[i]);
}
 revenue=C[0]*B[0];
 j=0;

for(i=0;i<a;i++)

{
if(i>0)
{
if(C[i]*B[i]>C[i-1]*B[i-1])
{
revenue=C[i]*B[i];
j=i;
}
}

}

printf("%s" , A[j]);

}

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Daily Challenge #187 - Most Sales

dev.to staff Feb 14 ・1 min read

Example

Test

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Scala

Haskell

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Example

Test

dev.to staff

Scala

Haskell

include

I created the Web Almanac. Ask me anything about the state of the web!

100DaysOfCoders are getting free plans at Vay

Carter Harrison - Mar 22

Reducing Readability?

Quinn Lashinsky - Mar 19

Hardest text file to parse 🚨

Carter Harrison - Mar 22

John and his Fences

JCowie - Mar 18

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