complete lab02

.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>

src/ca/bcit/comp3760/assign2/Lab2.java

@@ -0,0 +1,114 @@
+package ca.bcit.comp3760.assign2;
+
+import java.util.ArrayList;
+
+/**
+ * Lab2 Generates palindromes of length N with
+ * the characters A, B, and C.
+ *
+ * @author Braeden Sowinski
+ * @version 1.0.0
+ */
+public class Lab2
+{
+    /**
+     * generate a list of all palindrome sequences of a given length N
+     * for the characters A, B, and C.
+     * @param n length of palindrome to generate
+     * @return ArrayList of strings containing all palindromes of length n
+     */
+    public ArrayList<String> generatePalindromeSequences(final int n)
+    {
+        final ArrayList<String> sequences;
+        sequences = new ArrayList<>();
+
+        if (n < 1)
+        {
+            /* we can assume n in greater than 1, but we'll
+               check just in case. */
+            return sequences;
+        }
+        else if (n <= 2)
+        {
+            sequences.add("A".repeat(n));
+            sequences.add("B".repeat(n));
+            sequences.add("C".repeat(n));
+            return sequences;
+        }
+
+        final ArrayList<String> subsequences;
+        subsequences = generatePalindromeSequences(n - 2);
+
+        for (final char c : "ABC".toCharArray())
+        {
+            subsequences.forEach(sub -> sequences.add(c + sub + c));
+        }
+
+        return sequences;
+    }
+
+    /**
+     * morePalindromeSequences is a BONUS question that generates
+     * palindromes of length n, with c amount of characters. i.e.
+     * A, B, C, ... Cth character.
+     * @param n length palindrome
+     * @param nc number of characters in palindrome
+     */
+    public ArrayList<String> morePalindromeSequences(final int n, final int nc)
+    {
+        final String characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+
+        if (nc > characters.length())
+        {
+            return null;
+        }
+
+        final ArrayList<String> sequences;
+        sequences = new ArrayList<>();
+
+        if (n < 1)
+        {
+            /* we can assume n in greater than 1, but we'll
+               check just in case. */
+            return sequences;
+        }
+        else if (n <= 2)
+        {
+            for (int i = 0; i < nc; i++)
+            {
+                sequences.add((characters.charAt(i) + "").repeat(n));
+            }
+            return sequences;
+        }
+
+        final ArrayList<String> subsequences;
+        subsequences = generatePalindromeSequences(n - 2);
+
+        for (final char c : characters.substring(0, nc).toCharArray())
+        {
+            subsequences.forEach(sub -> sequences.add(c + sub + c));
+        }
+
+        return sequences;
+    }
+
+    /**
+     * main program entry for testing
+     * @param args unused
+     */
+    public static void main(final String[] args)
+    {
+        final Lab2 test;
+
+        test = new Lab2();
+
+        System.out.println("Generating ALL sequences of a given length:");
+        for (int i = 1; i <= 20; i++)
+        {
+            final ArrayList<String> sequences;
+            sequences = test.generatePalindromeSequences(i);
+            System.out.printf("Length %d produces %d sequences\n", i, sequences.size());
+            //System.out.println(sequences);
+        }
+    }
+}