Inital commitHEADmaster

1 files changed, 51 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;
+	}
+}