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 therovers so that their on-board cameras can get a complete view of thesurrounding terrain to send back to Earth.
A rover's position and location is represented by a combination of x and yco-ordinates and a letter representing one of the four cardinal compasspoints. The plateau is divided up into a grid to simplify navigation. Anexample position might be 0, 0, N, which means the rover is in the bottomleft corner and facing North.
In order to control a rover, NASA sends a simple string of letters. Thepossible letters are 'L', 'R' and 'M'. 'L' and 'R' makes the rover spin 90degrees 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, thelower-left coordinates are assumed to be 0,0.
The rest of the input is information pertaining to the rovers that havebeen deployed. Each rover has two lines of input. The first line gives therover's position, and the second line is a series of instructions tellingthe 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 roverwon't start to move until the first one has finished moving.
OUTPUT
The output for each rover should be its final co-ordinates and heading.
INPUT AND OUTPUT
Test Input:
5 5
1 2 N
LMLMLMLMM
3 3 E
MMRMMRMRRM
Expected Output:
1 3 N
5 1 E
==========
Answer:
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8 comments:
I'd be interested in seeing the source to you solution, but I'm getting a 404 error when I try to download the zip.
I think the link is repaired now .. please check and let me know .. :P
njoi
Yes, seem to be working now!
modified the code for a cleaner design (strategy pattern) today...
njoi
PS : GetEffectiveSteps() code is still not shared
#!/usr/bin/perl
use Switch;
my %direction = (
N => {
L => W,
R => E
},
S => {
L => E,
R => W
},
E => {
L => N,
R => S
},
W => {
L => S,
R => N
}
);
print "Input:\n";
my ($lower_x, $lower_y) = (0, 0);
my $upper_right_coordinates = ~STDIN~; #use <> instead of ~.
chomp $upper_right_coordinates;
my ($upper_x, $upper_y) = split(/ /, $upper_right_coordinates);
my $position1 = ~STDIN~;
chomp $position1;
my $instruction1 = ~STDIN~;
chomp $instruction1;
my $position2 = ~STDIN~;
chomp $position2;
my $instruction2 = ~STDIN~;
chomp $instruction2;
print "Output:\n";
my ($x, $y, $orientation);
($x, $y, $orientation) = get_final_position($position1, $instruction1);
if (check_coordinates($x, $y)) {
print "Rover1 can not move outside of the grid.\n";
}
else {
print "$x $y $orientation\n";
}
($x, $y, $orientation) = get_final_position($position2, $instruction2);
if (check_coordinates($x, $y)) {
print "Rover2 can not move outside of the grid.\n";
}
else {
print "$x $y $orientation\n";
}
sub get_final_position {
my ($position, $instruction) = @_;
my ($x, $y, $orientation) = split(/ /, $position);
my @instruction = split(//, $instruction);
foreach (@instruction) {
if ($_ eq 'M') {
($x, $y) = get_coordinates($x, $y, $orientation);
}
elsif ($_ eq 'L' || $_ eq 'R') {
$orientation = get_orientation($orientation, $_);
}
else {
next;
}
}
return ($x, $y, $orientation);
}
sub get_orientation {
my ($orientation, $direction) = @_;
return $direction{$orientation}{$direction};
}
sub get_coordinates {
my ($x, $y, $orientation) = @_;
switch ($orientation) {
case 'N' {return ($x, ++$y);}
case 'S' {return ($x, --$y);}
case 'E' {return (++$x, $y);}
case 'W' {return (--$x, $y);}
}
}
sub check_coordinates {
my ($x, $y) = @_;
($x < $lower_x || $x > $upper_x || $y < $lower_y || $y > $upper_y) ? return 1 : return 0;
}
the binary executes with right results, but not the code. Can soneone help me with the solution please?
Latest code (complete) is uploaded
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