Java Board Game

Problem Description

The project involves implementing in Java, a board game called IQ-focus made by the games developer SmartGames.

Objective

The game is a puzzle. At the start, the player selects a challenge which defines the color of each of the nine squares in the central board area. The objective is to place all ten colored playing pieces onto a board comprising 43 locations (indents). The player must place the pieces such that they: a) fit together correctly on the board, without overlaps or gaps, and b) satisfy the challenge.

A completed game:

Challenges

A game starts by choosing a challenge which specifies the color of the nine central squares. Here is the chosen challenge for the game above (this happens to be challenge 1 that comes with the game):

Solutions

Each challenge has just one solution. When we refer to solutions, we ignore piece rotations that take up the same space on the board. Such rotations are described as symmetric, which is defined in more detail below.

The following sequence shows one possible progression of a solution to the game above (note that the order in which the pieces are played is not important; this is just one possible ordering).

Board

The game is played on a board comprised of 43 locations arranged in a 9x5 grid. In the real-world game, each location consists of a square indent into which a piece may fit. In our game, locations are encoded as two digits, the first one identifying the column from 0 to 8, followed by another identifying the row from 0 to 4. For example, in the game above, the first piece is put on position 30 and the second is put on 32. Note that pieces are addressed as XY where X identifies the column where the left-most square of the piece is in, and Y identifies the row where the top square of the piece is in. Yellow dots in the diagram above indicate the point of reference (i.e. the top-most row and left-most column occupied by the piece).

Pieces

The game comprises 10 playing shapes, each of which is made of plastic and consists of three, four, or five connected squares (see the photo above). The pieces fit neatly into the indents in the plastic board formed by the 43 locations.

Each piece can be rotated at 90 degree increments, allowing for 4 different orientations. The following illustration shows all 40 possible combinations of the 10 pieces and 4 orientations. (Yellow dots indicate the point of reference for the piece's location, described below).

Strict Symmetry

Notice that piece f and piece g are symmetric, so rotating them twice will not change the shape (for example fxy0 is identical to fxy2). We describe that as 'strictly symmetric'. We ignore the redundant rotations with higher numberings (e.g. fxy2, fxy3, gxy2 and gxy3 are ignored).

Legal Piece Placements

For a piece placement to be valid, the following must be true:

• All squares comprising each piece must be placed on valid board locations (no part of a piece may be off the board).
• All squares comprising each piece must be placed on vacant board locations (pieces may not overlap).

Challenge Strings

A challenge string consists of a sequence of exactly nine characters, each describing the color of one square in the central 3x3 board area. There are four colors: White, Red, Blue and Green, which are encoded as 'W', 'R', 'B' and 'G' respectively.

For the sample challenge below, the challenge string is "RRRBWBBRB", which is achieved by tracing the central board area with this order:

Placement Strings

A placement string consists of between one and ten (inclusive) piece placements (pieces a to j). The placement string may not include any piece twice. A completed game must include ten piece placements. Each piece placement is described using four characters. For example, the game described above is characterized (when complete) by the string "a000b013c113d302e323f400g420h522i613j701". Note that the placement string is ordered (piece a first, and piece j last), which is a requirement for valid placement strings.

Piece Placement Strings

A piece placement string consists of four characters describing the location and orientation of one particular piece on the board:

• The first character identifies which of the ten shapes is being placed (a to j).
• The second character identifies which column the left of the piece is in (columns are labelled 0 to 9).
• The third character identifies which row the top of the piece is in (rows are labelled 0 to 4).
• The fourth character identifies which orientation the piece is in (0 to 3 for four rotations as illustrated above).

The image above shows the first and fourth characters for each of the pieces in each of their orientations (40 in total). For example, at top left, 'a0' describes piece 'a' at orientation '0'. Below it, 'b0' describes piece 'b' at orientation '0'. At the bottom right 'j3' describes piece 'j' at orientation '3'. And so on. A piece placement string starts and ends with these two characters and has two more in between which describe where the piece is placed.