Coin-Moving Explorer

This program lets you explore a certain type of coin-moving puzzle.

The goal of the coin-moving puzzles simulated by this program is to change one pattern into another by moving coins around. When the coins are moved, they must follow these rules:

1. All coins must remain on the table top. They can't be picked up and dropped into a location.

2. Only one coin can be moved at one time. A coin can't be used to move other coins.

3. A coin's destination must be firmly established by pushing it up against at least two other coins.

4. In this program, two coins that have a one-coin gap between them are insufficient to establish the destination of the moving coin. At least one more coin is needed to prevent the moving coin from being pushed through the gap.

How to use this program:

This program starts in "edit mode". Use the Edit check box to toggle edit mode on and off. While in edit mode, you can click on the circles in the grid to insert or remove a coin. Use edit mode to enter the starting coin pattern by clicking on the circles. The Initialize button removes all of the coins. Use the Size slider to change the number of circles that appears in the grid when the puzzle is initialized (to allow for big puzzles or for more maneuvering room).

Uncheck the Edit check box to try out a puzzle. To move a coin, click on it. The coin, and all legal destinations, will become highlighted. Click on one of the destination circles to move the coin. Keep moving coins until you reach the final pattern.

Your moves are recorded in the History panel. The first line in the panel will record the position of the first coin in the initial pattern (the coin that is furthest left in the highest row). This information lets people know how your initial coin pattern was positioned in the grid. Each move is recorded as four numbers. The first two numbers are the coordinates of the moved coin's starting location (row number and distance from the left). The second two numbers are the coordinates of the coin's ending location.

To copy your solution into a file, click on the Copy button, and press Ctrl-C to copy the text into your copy buffer. You can also transfer your solutions to other documents by selecting text in the History panel and using cut and paste techniques.

Whenever the mouse is passed over a circle, the circle's coordinates are shown in the At: field.

The Back button undoes previous moves. The Forward button redoes the moves. Press the Restart button to start at the beginning. You can use the Forward button after pressing Restart to review your moves graphically.

Some example puzzles:

Change the left pattern into the right pattern in the number of moves indicated by the arrow (or less). Patterns do not have to have the same orientation.