3 files changed, 180 insertions, 0 deletions

diff --git a/labs/lab05_permutation/Permutation.java b/labs/lab05_permutation/Permutation.java
new file mode 100644
index 0000000..b0cc541
--- /dev/null
+++ b/labs/lab05_permutation/Permutation.java
@@ -0,0 +1,51 @@
+import java.util.ArrayList;
+
+
+public class Permutation
+{
+	public static ArrayList<ArrayList<Integer>> permutation(final ArrayList<Integer> olist)
+	{
+		ArrayList<Integer> list = new ArrayList<Integer>();
+		for(Integer i : olist)
+		{
+			list.add(i);
+		}
+		//System.out.println("[ME]Permutateing " + list);
+		ArrayList<ArrayList<Integer>> output = new ArrayList<ArrayList<Integer>>();
+		//System.out.println("[ME] Size is " + list.size());
+		if(list.size() <= 1)
+		{
+			output.add(list);
+		}
+		
+		else
+		{
+			ArrayList<Integer> newlist = list;
+			for(Integer i=0; i < list.size(); i++)
+			{
+				//System.out.println("[ME]First element for this permutation is " + newlist.get(0));
+				Integer firstEntry = newlist.remove(0);
+				for(ArrayList<Integer> l : permutation(newlist))
+				{
+					//System.out.println("[ME]This arraylist" + l);
+					ArrayList<Integer> tmp1 = new ArrayList<Integer>();
+					//ArrayList<Integer> tmp2 = new ArrayList<Integer>();
+					tmp1.add(firstEntry);
+					for(Integer i2 : l)
+					{
+						tmp1.add(i2);
+						//tmp2.add(i2);
+					}
+					//tmp2.add(firstEntry);
+					//System.out.println("[ME] This full permutation is " + tmp1 + ", i is " + i + " and size is " + list.size());
+					output.add(tmp1);
+					//output.add(tmp2);
+				}
+				newlist.add(firstEntry);
+			}
+		}
+		
+		//System.out.println("[ME] Returning " + output);
+		return output;
+	}
+}
diff --git a/labs/lab05_permutation/PermutationTester.java b/labs/lab05_permutation/PermutationTester.java
new file mode 100644
index 0000000..2c56d3b
--- /dev/null
+++ b/labs/lab05_permutation/PermutationTester.java
@@ -0,0 +1,129 @@
+import java.util.ArrayList;
+
+
+public class PermutationTester
+{
+	public static void main(String[] args)
+	{
+		int point = 0;
+		ArrayList<Integer> list = new ArrayList<Integer>();
+		ArrayList<ArrayList<Integer>> result;
+		
+		for(int i = 1; i <= 5; i++)
+		{
+			System.out.println("Testing permutation with " + i + " element(s)");
+			list.add(i);
+			/*Take this out*///System.out.println("[ME]Before" + list);
+			result = Permutation.permutation(list);
+			/*Take this out*///System.out.println("[ME]After" + list);
+			System.out.println("Your code said, the permutation of " + list + " is as follows:");
+			System.out.println(result);
+			
+			boolean result1 = checkPermutationSize(list, result);
+			boolean result2 = checkPermutation(list, result);
+			if(result1 && result2)
+			{
+				point += 2;
+				System.out.println("Your current point is " + point + ".");
+				System.out.println();
+			}
+			else
+			{
+				System.out.println("Your current point is " + point + ".");
+				System.out.println("There is someting wrong with your method permutation().");
+				System.out.println("Fix your code and run this tester class again.");
+				break;
+			}
+		}
+	}
+	
+	private static int factorial(int n)
+	{
+		if(n == 0)
+			return 1;
+		else
+			return n * factorial(n - 1);
+	}
+	
+	private static boolean checkPermutation(ArrayList<Integer> list, ArrayList<ArrayList<Integer>> result)
+	{
+		int numberOfElements = list.size();
+		int numberOfResults = result.size();
+		
+		System.out.print("Check the size of each element: ");
+		for(int i = 0; i < numberOfResults; i++)
+		{
+			if(result.get(i).size() != list.size())
+			{
+				System.out.println("FAIL");
+				System.out.println("Every element in your result should contains " + numberOfElements + " elements.");
+				System.out.println("But an element of your result contains " + result.get(i).size() + " elements.");
+				return false;
+			}
+		}
+		
+		System.out.println("PASS");
+		
+		System.out.print("Check for duplicate elements: ");
+		
+		for(int i = 0; i < numberOfResults; i++)
+		{
+			ArrayList<Integer> temp = result.get(i);
+			
+			for(int j = i + 1; j < numberOfResults; j++)
+			{
+				if(temp.equals(result.get(j)))
+				{
+					System.out.println("FAIL");
+					System.out.println("Your result contains duplicate items which is " + temp + ".");
+					return false;
+				}
+			}
+		}
+		
+		System.out.println("PASS");
+
+		System.out.print("Check each element: ");
+		for(int i = 0; i < numberOfResults; i++)
+		{
+			ArrayList<Integer> temp = result.get(i);
+			
+			for(int j = 0; j < numberOfElements; j++)
+			{
+				int aNumber = list.get(j);
+				
+				if(!temp.contains(aNumber))
+				{
+					System.out.println("FAIL");
+					System.out.println("The element " + temp + " in your result does not contain every element in " + list + ".");
+				}
+			}
+		}
+		
+		System.out.println("PASS");
+		
+		return true;
+	}
+	
+	private static boolean checkPermutationSize(ArrayList<Integer> list, ArrayList<ArrayList<Integer>> result)
+	{
+		System.out.print("Check the size of the result: ");
+		
+		int numberOfElements = list.size();
+		int numberOfResults = result.size();
+		
+		if(factorial(numberOfElements) != numberOfResults)
+		{
+			System.out.println("FAIL");
+			System.out.println("   The list " + list + " contains " + numberOfElements + " elements.");
+			System.out.println("   Permutation of " + list + " should contains " + factorial(numberOfElements) + "elements.");
+			System.out.println("   But your result contains " + numberOfResults + " elements.");
+			return false;
+		}
+		else
+		{
+			System.out.println("PASS");
+			return true;
+		}
+	}
+}
\ No newline at end of file
diff --git a/labs/lab05_permutation/lab05_permutation.pdf b/labs/lab05_permutation/lab05_permutation.pdf
new file mode 100644
index 0000000..fffd055
--- /dev/null
+++ b/labs/lab05_permutation/lab05_permutation.pdf