RosettaCodeData/Task/Dinesmans-multiple-dwelling.../Java/dinesmans-multiple-dwelling...

65 lines
1.9 KiB
Java

import java.util.*;
class DinesmanMultipleDwelling
{
private static void generatePermutations(String[] apartmentDwellers, Set<String> set, String curPermutation)
{
for (String s : apartmentDwellers)
{
if (!curPermutation.contains(s))
{
String nextPermutation = curPermutation + s;
if (nextPermutation.length() == apartmentDwellers.length)
set.add(nextPermutation);
else
generatePermutations(apartmentDwellers, set, nextPermutation);
}
}
return;
}
private static boolean topFloor(String permutation, String person)
{ return permutation.endsWith(person); }
private static boolean bottomFloor(String permutation, String person)
{ return permutation.startsWith(person); }
public static boolean livesAbove(String permutation, String upperPerson, String lowerPerson)
{ return permutation.indexOf(upperPerson) > permutation.indexOf(lowerPerson); }
public static boolean adjacent(String permutation, String person1, String person2)
{ return (Math.abs(permutation.indexOf(person1) - permutation.indexOf(person2)) == 1); }
private static boolean isPossible(String s)
{
// Conditions here
if (topFloor(s, "B"))
return false;
if (bottomFloor(s, "C"))
return false;
if (topFloor(s, "F") || bottomFloor(s, "F"))
return false;
if (!livesAbove(s, "M", "C"))
return false;
if (adjacent(s, "S", "F"))
return false;
if (adjacent(s, "F", "C"))
return false;
return true;
}
public static void main(String[] args)
{
Set<String> set = new HashSet<String>();
generatePermutations(new String[] { "B", "C", "F", "M", "S" }, set, "");
for (Iterator<String> iterator = set.iterator(); iterator.hasNext(); )
{
String permutation = iterator.next();
if (!isPossible(permutation))
iterator.remove();
}
for (String s : set)
System.out.println("Possible arrangement: " + s);
}
}