BunnyPuzzle

Problem Statement

NOTE: This problem statement contains images that may not display properly if viewed outside of the applet.

Taro and Hanako are playing Bunny Puzzle. There are several bunnies standing on a line. You are given a int[] bunnies, where each element is the initial position of a single bunny.

They must perform the following routine exactly once:

1. Choose two different bunnies A and B, located at points a and b, respectively.
2. A jumps over B and lands at point 2*b-a.

The jump is not allowed if another bunny is already at point 2*b-a.



The jump is also not allowed if A jumps over more than one bunny.





Return the number of different ways in which Taro and Hanako can choose the pair of bunnies A and B. "A jumps over B" and "B jumps over A" are considered to be different.

Definition

Class:

BunnyPuzzle

Method:

theCount

Parameters:

int[]

Returns:

int

Method signature:

int theCount(int[] bunnies)

(be sure your method is public)

Constraints

• bunnies will contain between 2 and 50 elements, inclusive.
• Each element of bunnies will be between -10^6 and 10^6, inclusive.
• bunnies will be sorted in strictly ascending order.

Examples

1. {5, 8}

   Returns: 2

   There are two possible moves: A bunny jumps from 5 to 11 A bunny jumps from 8 to 2

2. {-1, 0, 1}

   Returns: 2

   There are two possible moves: A bunny jumps from 0 to -2 A bunny jumps from 0 to 2

3. {0, 1, 3}

   Returns: 3

   There are three possible moves: A bunny jumps from 0 to 2 A bunny jumps from 1 to -1 A bunny jumps from 1 to 5

4. {-677, -45, -2, 3, 8, 29, 384, 867}

   Returns: 7

5. {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}

   Returns: 2