Add new concept exercise : numbers (exercism#2875)

* First * Add : config.json authors & editor * Add : exchange file exchange_test / exchange * Fix : typo Line 2 from .exchange import * -> from exchange import * * Fix : Forder Name * Fix : Folder Name * Added example and instructions. (#6) added : currency-exchange/.meta/example.py added : currency-exchange/.docs/instructions.md * Added design.md (#7) * added design.md added : currency-exchange/.meta/design.md * Added hint.md (#8) Added hint.md (#8) * Add : hint.md (#10) * Delete .DS_Store * Add : hint.md (#9) Add : hint.md Solving Conflict * Add introduction.md (#8) * Fix: typo (#11) fix exchangable to exchangeable fix "Chandler want" to "Chandler wants" in instructions.md * Change File_name & Prettier (#12) * Fix : Prettier (#13) * Add : slug to config.json (#14) * Fix config (#15) * Fix introduction.md (#16) * Fix instructions.md (#17) * Fixed instructions.md Fixed grammatical errors in instructions.md based on BethanyG's review. Co-authored-by: Limm-jk <[email protected]> Co-authored-by: Junkyu Lim <[email protected]> * add testcase * Added problem "6. Calculate unexchangeable value" (#19) * Added new problem "Calculate unexchangeable value" Added modular arithmetic problem Calculate unexchangeable value * Added new problem "Calculate unexchangeable value" (example.py, exchange.py) Modified example.py, exchange.py * Modified Calculated unexchangeable value Modified `unexchangeable_value()` function's expected return type to be `int` * added new lines at the end of file * applied prettier on instructions.md Co-authored-by: Limm-jk <[email protected]> Co-authored-by: Junkyu Lim <[email protected]> * Add : Problem Design (#20) * Update languages/config.json we changed the concept name, so needed to update file. * Update languages/exercises/concept/currency-exchange/.docs/introduction.md * Update languages/exercises/concept/currency-exchange/.docs/introduction.md * Update languages/exercises/concept/currency-exchange/.docs/introduction.md * Update languages/exercises/concept/currency-exchange/.docs/introduction.md * Update languages/exercises/concept/currency-exchange/.meta/config.json we've decided to name the stub and test files for the concept and not the story. * Update languages/exercises/concept/currency-exchange/.meta/design.md minor typo * Update languages/exercises/concept/currency-exchange/exchange_test.py * Update languages/exercises/concept/currency-exchange/exchange_test.py * Update languages/exercises/concept/currency-exchange/.docs/introduction.md Co-authored-by: Yunseon Choi <[email protected]> * Update languages/config.json removed arithmetic as a concept until we get the about.md file made. * Update languages/exercises/concept/currency-exchange/.meta/config.json reverting file name change and deferring to different PR. This is currently breaking a CI test. Co-authored-by: Yoggy <[email protected]> Co-authored-by: Seunghun Yang <[email protected]> Co-authored-by: Ticktakto <[email protected]> Co-authored-by: Yunseon Choi <[email protected]> Co-authored-by: wnstj2007 <[email protected]> Co-authored-by: BethanyG <[email protected]>
ErikSchierboom · Jan 21, 2021 · ebba91e · ebba91e
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diff --git a/exercises/concept/currency-exchange/.docs/hints.md b/exercises/concept/currency-exchange/.docs/hints.md
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+# General
+
+- [The Python Numbers Tutorial](https://docs.python.org/3/tutorial/introduction.html#numbers) and [Python numeric types](https://docs.python.org/3.9/library/stdtypes.html#numeric-types-int-float-complex) can be a great introduction.
+
+## 1. Estimating exchangeable value
+
+- You can use the [division operator](https://docs.python.org/3/tutorial/introduction.html#numbers) to get the value of exchanged currency.
+
+## 2. Changes after exchanging
+
+- You can use the [substraction operator](https://docs.python.org/3/tutorial/introduction.html#numbers) to get the amount of changes.
+
+## 3. Calculate value of bills
+
+- You can use the [multiplication operator](https://docs.python.org/3/tutorial/introduction.html#numbers) to get the value of bills.
+
+## 4. Calculate number of bills
+
+- You need to divide `budget` into `denomination`.
+- You need to use type casting _int_ to get exact number of bill.
+- To remove decimal places from a `float`, you can convert it to `int`.
+
+  **Note:** The `//` operator also does floor division. But, if the operand has `float`, the result is still `float`.
+
+## 5. Calculate exchangeable value
+
+- You need to calculate `spread` percent of `exchange_rate` using multiplication operator and add it to `exchange_rate` to get the exchanged currency.
+- Actual rate need to be computed! add exchange rate and exchange fee.
+- You can get exchanged money affected by commission by using divide operation and type casting _int_.
diff --git a/exercises/concept/currency-exchange/.docs/instructions.md b/exercises/concept/currency-exchange/.docs/instructions.md
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+Your friend Chandler plans to visit exotic countries all around the world. Sadly, Chandler's math skills aren't good. He's pretty worried about being scammed with currency exchange during his trip - and he wants you to make a currency calculator for him. Here's his specification for the app:
+
+## 1. Estimate value after exchange
+
+Create the `estimate_value()` function, where `budget` & `exchange_rate` are the two required parameters:
+
+1. `budget` : the amount of money you are planning to exchange.
+2. `exchange_rate` : unit value of the foreign currency.
+
+This function should return the estimated value of the foreign currency you can receive based on your `budget` and the current `exchange rate`.
+
+**Note:** If your currency is USD and you want to exchange USD for EUR with an exchange rate of `1.20`, then `1.20 USD` == `1 EUR`.
+
+```python
+>>> estimate_value(127.5, 1.2)
+106.25
+```
+
+## 2. Calculate currency left after an exchange
+
+Create the `get_change()` function, where `budget` & `exchanging_value` are the two required parameters:
+
+1. `budget` : amount of money you own.
+2. `exchanging_value` : amount of your money you want to exchange now.
+
+This function should return the amount left of your starting currency after exchanging `exchanging_value`.
+
+```python
+>>> get_change(127.5, 120)
+7.5
+```
+
+## 3. Calculate value of bills
+
+Create the `get_value()` function, with parameters `denomination` & `number_of_bills`
+
+1. `denomination` : the value of a single bill.
+2. `number_of_bills` : amount of bills you received.
+
+This function should return the total value of bills you now have.
+
+```python
+>>> get_value(5, 128)
+640
+```
+
+## 4. Calculate number of bills
+
+Create the `get_number_of_bills()` function, with parameters `budget` & `denomination`
+
+1. `budget` : amount of money you are planning to exchange.
+2. `denomination` : the value of a single bill.
+
+This function should return the number of bills after exchanging all your money.
+
+```python
+>>> get_number_of_bills(127.5, 5)
+25
+```
+
+## 5. Calculate value after exchange
+
+Create the `exchangeable_value()` function, with parameter `budget`, `exchange_rate`, `spread`, & `denomination`.
+
+1. `budget` : amount of your money you are planning to exchange.
+2. `exchange_rate` : unit value of the foreign currency.
+3. `spread` : percentage taken as exchange fee.
+4. `denomination` : the value of a single bill.
+
+This function should return the maximum value you can get considering the `budget`, `exchange_rate`, `spread`, & `denomination`.
+
+**Note:** If `1 EUR` == `1.20 USD` and the spread is `10%`, the _actual exchange rate_ becomes `1 EUR` == `1.32 USD`.
+
+```python
+>>> exchangeable_value(127.25, 1.20, 10, 20)
+80
+>>> exchangeable_value(127.25, 1.20, 10, 5)
+95
+```
+
+## 6. Calculate unexchangeable value
+
+Create the `unexchangeable_value()` function, with parameter `budget`, `exchange_rate`, `spread`, & `denomination`.
+
+1. `budget` : amount of your money you are planning to exchange.
+2. `exchange_rate` : unit value of the foreign currency.
+3. `spread` : percentage taken as exchange fee.
+4. `denomination` : the value of a single bill.
+
+This function should return the unexchangeable value considering the `budget`, `exchange_rate`, `spread`, & `denomination`.
+
+**Note:** Returned value should be `int` type.
+
+```python
+>>> unexchangeable_value(127.25, 1.20, 10, 20)
+16
+>>> unexchangeable_value(127.25, 1.20, 10, 5)
+1
+```
diff --git a/exercises/concept/currency-exchange/.docs/introduction.md b/exercises/concept/currency-exchange/.docs/introduction.md
@@ -0,0 +1,68 @@
+## Numbers
+
+There are three different kinds of built-in numbers in Python : `ints`, `floats`, and `complex`. However, in this exercise you'll be dealing only with `ints` and `floats`.
+
+### ints
+
+`ints` are whole numbers. e.g. `1234`, `-10`, `20201278`.
+
+### floats
+
+`floats` are numbers containing a decimal point. e.g. `0.0`,`3.14`,`-9.01`. Floats in Python are of [_arbitrary precision_][arbitrary-precision].
+
+You can see more details in the following resources:
+
+- [Python numeric type documentation][numeric-type-docs]
+- [Documentation for `int()` built in][`int()` built in]
+- [Documentation for `float()` built in][`float()` built in]
+
+## Arithmetic
+
+Python fully supports arithmetic between `ints` and `floats`. It will convert narrower numbers to match their less narrow counterparts when used with the binary arithmetic operators (`+`, `-`, `*`, `/`, `//`, and `%`). When division with `/`, `//` returns the quotient and `%` returns the remainder.
+
+Python considers `ints` narrower than `floats`. So, using a float in an expression ensures the result will be a float too. However, when doing division, the result will always be a float, even if only integers are used.
+
+```python
+# The int is widened to a float here, and a float type is returned.
+>>> 3 + 4.0
+7.0
+>>> 3 * 4.0
+12.0
+>>> 3 - 2.0
+1.0
+# Division always returns a float.
+>>> 6 / 2
+3.0
+>>> 7 / 4
+1.75
+# Calculating remainders.
+>>> 7 % 4
+3
+>>> 2 % 4
+2
+>>> 12.75 % 3
+0.75
+```
+
+If an int result is needed, you can use `//` to truncate the result.
+
+```python
+>>> 6 // 2
+3
+>>> 7 // 4
+1
+```
+
+To convert a float to an integer, you can use `int()`. Also, to convert an integer to a float, you can use `float()`.
+
+```python
+>>> int(6 / 2)
+3
+>>> float(1 + 2)
+3.0
+```
+
+[arbitrary-precision]: https://en.wikipedia.org/wiki/Arbitrary-precision_arithmetic#:~:text=In%20computer%20science%2C%20arbitrary%2Dprecision,memory%20of%20the%20host%20system.
+[numeric-type-docs]: https://docs.python.org/3/library/stdtypes.html#typesnumeric
+[`int()` built in]: https://docs.python.org/3/library/functions.html#int
+[`float()` built in]: https://docs.python.org/3/library/functions.html#float
diff --git a/exercises/concept/currency-exchange/.meta/config.json b/exercises/concept/currency-exchange/.meta/config.json
@@ -0,0 +1,28 @@
+{
+  "authors": [
+    {
+      "github_username": "Ticktakto",
+      "exercism_username": "Ticktakto"
+    },
+    {
+      "github_username": "Yabby1997",
+      "exercism_username": "Yabby1997"
+    },
+    {
+      "github_username": "limm-jk",
+      "exercism_username": "limm-jk"
+    },
+    {
+      "github_username": "OMEGA-Y",
+      "exercism_username": "OMEGA-Y"
+    },
+    {
+      "github_username": "wnstj2007",
+      "exercism_username": "wnstj2007"
+    }
+  ],
+  "editor": {
+    "solution_files": ["exchange.py"],
+    "test_files": ["exchange_test.py"]
+  }
+}
diff --git a/exercises/concept/currency-exchange/.meta/design.md b/exercises/concept/currency-exchange/.meta/design.md
@@ -0,0 +1,9 @@
+## Goal
+
+The goal of this exercise is to teach the student how to use arithmetic operators and type casting between `int` and `float` in Python
+
+## Learning objectives
+
+- use `+`, `-`, `*`, `/` to add, subtract, multiply, divide numbers(`int` and `float`).
+- use `int()` to cast `float` to `int`.
+- use `%` to calculate remainders.
diff --git a/exercises/concept/currency-exchange/.meta/example.py b/exercises/concept/currency-exchange/.meta/example.py
@@ -0,0 +1,27 @@
+def estimate_value(budget, exchange_rate):
+	return budget / exchange_rate
+
+
+def get_changes(budget, exchanging_value):
+	return budget - exchanging_value
+
+
+def get_value(denomination, number_of_bills):
+	return number_of_bills * denomination
+
+
+def get_number_of_bills(budget, denomination):
+	return int(budget / denomination)
+
+
+def exchangeable_value(budget, exchange_rate, spread, denomination):
+	exchange_fee = (exchange_rate / 100) * spread
+	actual_rate = exchange_rate + exchange_fee
+	exchangeable_amount = int((budget / actual_rate) / denomination)
+	return exchangeable_amount * denomination
+
+def unexchangeable_value(budget, exchange_rate, spread, denomination):
+	exchange_fee = (exchange_rate / 100) * spread
+	actual_rate = exchange_rate + exchange_fee
+	unexchangeable_amount = int((budget / actual_rate) % denomination)
+	return unexchangeable_amount
diff --git a/exercises/concept/currency-exchange/exchange.py b/exercises/concept/currency-exchange/exchange.py
@@ -0,0 +1,22 @@
+def estimate_value(budget, exchange_rate):
+    pass
+
+
+def get_change(budget, exchanging_value):
+    pass
+
+
+def get_value(denomination_value, number_of_bills):
+    pass
+
+
+def get_number_of_bills(budget, denomination):
+    pass
+
+
+def exchangeable_value(budget, exchange_rate, spread, minimum_denomination):
+    pass
+
+
+def unexchangeable_value(budget, exchange_rate, spread, denomination):
+    pass
diff --git a/exercises/concept/currency-exchange/exchange_test.py b/exercises/concept/currency-exchange/exchange_test.py
@@ -0,0 +1,91 @@
+import unittest
+from numbers import *
+
+
+class TestNumbers(unittest.TestCase):
+
+    # Problem 1
+    def test_estimate_value(self):
+        input_data = [
+            # input : budget, exchange_rate
+            (100000, 0.84),
+            (700000, 10.1)
+        ]
+        output_data = [119047, 69306]
+        for input, output in zip(input_data, output_data):
+            with self.subTest(input=input, output=output):
+                self.assertEqual(int(estimate_value(input[0], input[1])), output)
+
+    # Problem 2
+    def test_get_change(self):
+        input_data = [
+            # input : budget, exchanging_value
+            (463000, 5000),
+            (1250,120),
+            (15000,1380)
+        ]
+        output_data = [458000, 1130, 13620]
+        for input, output in zip(input_data, output_data):
+            with self.subTest(input=input, output=output):
+                self.assertEqual(get_change(input[0], input[1]), output)
+
+    # Problem 3
+    def test_get_value(self):
+        input_data = [
+            # input : denomination_value, number_of_bills
+            (10000, 128),
+            (50, 360),
+            (200, 200)
+        ]
+        output_data = [1280000, 18000, 40000]
+        for input, output in zip(input_data, output_data):
+            with self.subTest(input=input, output=output):
+                self.assertEqual(get_value(input[0], input[1]), output)
+
+    # Problem 4
+    def test_get_number_of_bills(self):
+        input_data = [
+            # input : budget, denomination
+            (163270, 50000),
+            (54361, 1000)
+        ]
+        output_data = [3,54]
+        for input, output in zip(input_data, output_data):
+            with self.subTest(input=input, output=output):
+                self.assertEqual(get_number_of_bills(input[0], input[1]), output)
+
+    # Problem 5
+    def test_exchangeable_value(self):
+        input_data = [
+            # input : budget, exchange_rate, spread, minimum_denomination
+            (100000, 10.61, 10, 1),
+            (1500, 0.84, 25, 40),
+            (470000, 1050, 30, 10000000000),
+            (470000, 0.00000009, 30, 700),
+            (425.33, 0.0009, 30, 700)
+        ]
+        output_data = [8568, 1400, 0, 4017094016600, 363300]
+        for input, output in zip(input_data, output_data):
+            with self.subTest(input=input, output=output):
+                self.assertEqual(exchangeable_value(input[0], input[1], input[2], input[3]), output)
+
+    # Problem 6
+    def test_unexchangeable_value(self):
+
+        #exchangeable : 80, actual_rate : 1.3199999999999998, unexchangeable : 16.40151515151517
+        #input : budget, exchange_rate, spread, denomination
+        input_data = [
+
+            (100000, 10.61, 10, 1),
+            (1500, 0.84, 25, 40),
+            (425.33, 0.0009, 30, 700),
+            (12000, 0.0096, 10, 50)
+        ]
+
+        output_data = [0, 28, 229, 13]
+
+        for input, output in zip(input_data, output_data):
+            with self.subTest(input=input, output=output):
+                self.assertEqual(unexchangeable_value(input[0], input[1], input[2], input[3]), output)
+
+