Problem Statement
You have a set of cards, each with a number from 1 through 10 printed on it. The values of all the cards you have are given in int[] cards.
If you randomly select two cards, what are the chances they have the same value?
Definition
- Class:
- PickTwoMatch
- Method:
- chance
- Parameters:
- int[]
- Returns:
- double
- Method signature:
- double chance(int[] cards)
- (be sure your method is public)
Constraints
- cards will contain between 2 and 50 elements, inclusive.
- Each element of cards will be between 1 and 10, inclusive.
Examples
{ 1, 1, 1 }Returns: 1.0
With all the cards the same value, the two selected are guaranteed to match.{ 1, 2, 2 }Returns: 0.3333333333333333
There are three ways to pick two cards, and exactly one of those three gives a match.{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }Returns: 0.0
It's pretty hard to get a match when all the cards are different.