h3. PROBLEM: MARS ROVERS

A squad of robotic rovers are to be landed by NASA on a plateau on Mars. This plateau, which is curiously rectangular, must be navigated by the rovers so that their on-board cameras can get a complete view of the surrounding terrain to send back to Earth.

A rover's position and location is represented by a combination of x and y co-ordinates and a letter representing one of the four cardinal compass points. The plateau is divided up into a grid to simplify navigation. An example position might be 0, 0, N, which means the rover is in the bottom left corner and facing North.

In order to control a rover, NASA sends a simple string of letters. The possible letters are 'L', 'R' and 'M'. 'L' and 'R' makes the rover spin 90 degrees left or right respectively, without moving from its current spot. 'M' means move forward one grid point, and maintain the same heading.

Assume that the square directly North from (x, y) is (x, y+1).

INPUT: The first line of input is the upper-right coordinates of the plateau, the lower-left coordinates are assumed to be 0,0.

The rest of the input is information pertaining to the rovers that have been deployed. Each rover has two lines of input. The first line gives the rover's position, and the second line is a series of instructions telling the rover how to explore the plateau.

The position is made up of two integers and a letter separated by spaces, corresponding to the x and y co-ordinates and the rover's orientation.

Each rover will be finished sequentially, which means that the second rover won't start to move until the first one has finished moving.

h3. OUTPUT

The output for each rover should be its final co-ordinates and heading.

h3. INPUT AND OUTPUT

h4. Test Input:

5 5 1 2 N LMLMLMLMM 3 3 E MMRMMRMRRM

h4. Expected Output:

1 3 N 5 1 E

h3. Executing the code

This application can be run either from the command prompt or through the ant build script's 'run' target.

h4. Executing from the command prompt:

If running from the command prompt: Please ensure that the compiled source/jar is in classpath. Execute using the following command:

PROMPT:> java com.thoughtworks.rover.RunRoversMain validInput.txt

Note: This main execution class requires the input to be passed in through a inputfile and the file name with full path should be given as argument parameter as shown above.

h4. Executing as an Ant target:

The 'run' target in the Ant build script can also be used to execute the RunRoversMain. In this case, the file name with full path can be set through the property, 'inputFile' defined in build script as follows:

In build.xml:

<property name="inputFile" value="validInput.txt"/>

With Ant executable in the path we can run the application as follows:

PROMPT:> ant run

Note: If encountered with problem of executing junit test cases, please make sure the junit.jar is in the Ant's classpath or you can simply copy the junit.jar into the $ANT_HOME/lib directory.