wehub-resource-sync
dde272c4b8
i18n - Build Validation / Validate i18n Builds (24) (push) Has been cancelled
CI - Node.js / Lint (24) (push) Has been cancelled
CI - Node.js / Build (24) (push) Has been cancelled
CI - Node.js / Test (24) (push) Has been cancelled
CI - Node.js / Test - Upcoming Changes (24) (push) Has been cancelled
CI - Node.js / Test - i18n (italian, 24) (push) Has been cancelled
CI - Node.js / Test - i18n (portuguese, 24) (push) Has been cancelled
CD - Docker - GHCR Images / Build and Push Images (push) Has been cancelled
91 lines
1.9 KiB
Markdown
91 lines
1.9 KiB
Markdown
---
|
|
id: 68ee9e3066cfd4eb2328e8a8
|
|
title: "Challenge 89: Counting Cards"
|
|
challengeType: 29
|
|
dashedName: challenge-89
|
|
---
|
|
|
|
# --description--
|
|
|
|
A standard deck of playing cards has 13 unique cards in each suit. Given an integer representing the number of cards to pick from the deck, return the number of unique combinations of cards you can pick.
|
|
|
|
- Order does not matter. Picking card A then card B is the same as picking card B then card A.
|
|
|
|
For example, given `52`, return `1`. There's only one combination of 52 cards to pick from a 52 card deck. And given `2`, return `1326`, There's 1326 card combinations you can end up with when picking 2 cards from the deck.
|
|
|
|
# --hints--
|
|
|
|
`combinations(52)` should return `1`.
|
|
|
|
```js
|
|
({test: () => { runPython(`
|
|
from unittest import TestCase
|
|
TestCase().assertEqual(combinations(52), 1)`)
|
|
}})
|
|
```
|
|
|
|
`combinations(1)` should return `52`.
|
|
|
|
```js
|
|
({test: () => { runPython(`
|
|
from unittest import TestCase
|
|
TestCase().assertEqual(combinations(1), 52)`)
|
|
}})
|
|
```
|
|
|
|
`combinations(2)` should return `1326`.
|
|
|
|
```js
|
|
({test: () => { runPython(`
|
|
from unittest import TestCase
|
|
TestCase().assertEqual(combinations(2), 1326)`)
|
|
}})
|
|
```
|
|
|
|
`combinations(5)` should return `2598960`.
|
|
|
|
```js
|
|
({test: () => { runPython(`
|
|
from unittest import TestCase
|
|
TestCase().assertEqual(combinations(5), 2598960)`)
|
|
}})
|
|
```
|
|
|
|
`combinations(10)` should return `15820024220`.
|
|
|
|
```js
|
|
({test: () => { runPython(`
|
|
from unittest import TestCase
|
|
TestCase().assertEqual(combinations(10), 15820024220)`)
|
|
}})
|
|
```
|
|
|
|
`combinations(50)` should return `1326`.
|
|
|
|
```js
|
|
({test: () => { runPython(`
|
|
from unittest import TestCase
|
|
TestCase().assertEqual(combinations(50), 1326)`)
|
|
}})
|
|
```
|
|
|
|
# --seed--
|
|
|
|
## --seed-contents--
|
|
|
|
```py
|
|
def combinations(cards):
|
|
|
|
return cards
|
|
```
|
|
|
|
# --solutions--
|
|
|
|
```py
|
|
from math import factorial
|
|
def combinations(cards):
|
|
n = 52
|
|
|
|
return factorial(n) // (factorial(cards) * factorial(n - cards))
|
|
```
|