Problems › JavaScript › games
Find a card after drawing
A card game draws a number of cards from the top of a deck. Find which card ends up at a given position in the remaining stack.
- Discard the top draws cards from the deck.
- Return the card at the given position index in what remains.
- If the position does not exist in the remaining deck, return -1.
cardPosition(deck: list<int>, draws: int, position: int) → int
Where you start
function cardPosition(deck, draws, position) {
}Worked examples
| Call | Result |
|---|---|
cardPosition([10,20,30,40,50], 2, 1) | 40 |
cardPosition([1,2,3], 0, 0) | 1 |
cardPosition([1,2,3], 3, 0) | -1 |
cardPosition([5,6,7,8], 3, 0) | 8 |
Hint
The answer lives at index draws + position in the original deck, if that index is in bounds.
Reference solution in JavaScript
function cardPosition(deck, draws, position) {
const idx = draws + position;
return idx < deck.length ? deck[idx] : -1;
}