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Competition Arena > ThreeCardsDraw

ThreeCardsDraw

Rookie SRM 17 · 2022-09-22 · by erinn

Rookie SRM 17 · 2022-09-22 · by erinn · Advanced Math
Class Name: ThreeCardsDraw
Return Type: double
Method Name: totalChance
Arg Types: (int)
Problem Statement

Problem Statement

You have a standard deck of playing cards, containing 52 cards in 4 suits and 13 values. The values are Ace (1), 2, 3, 4, 5, 6, 7, 8, 9, 10, Jack (10), Queen (10), and King (10).

You are given int total. If you randomly select three cards--without replacement--from the deck, what is the probability their values will add up to total?

Notes

  • Notes that aces have a value of 1, while jacks, queens and kings have a value of 10.

Constraints

  • total will be between 3 and 30, inclusive.
Examples
0)
3
Returns: 1.8099547511312217E-4

The only way this can happen is to pick three of the four aces.

1)
30
Returns: 0.025339366515837104
2)
5
Returns: 0.0021719457013574662

There's a few ways to select three cards and get a total of 5.

3)
15
Returns: 0.05085972850678733
4)
20
Returns: 0.06660633484162896

Submissions are judged against all 6 archived test cases, of which 5 are shown here. Case numbers match the judge’s.

Coding Area

Language: C++17 · define a public class ThreeCardsDraw with a public method double totalChance(int total) · 6 test cases · 2 s / 256 MB per case

Submitting as anonymous