Subsequence.java :

package cmsc256; import java.io.*; import java.util.*; /** * Determine if one sequence of words is a subsequence of a second. */ public class Subsequence { public static void main(String args[]) { List s1, s2; System.out.println("We need two sequences of words."); s1 = getSequence("Enter the first sequence (s1) all on a single line."); s2 = getSequence("Enter the second sequence (s2) all on a single line."); System.out.println("s1 is " + s1); System.out.println("s2 is " + s2); System.out.println("Is s1 a subsequence of s2: " + subSequence(s1,s2)); System.out.println("Is s2 a subsequence of s1: " + subSequence(s2,s1)); testSubSequence(); } /** * subSequence - determine if one sequence is a subsequence of the other * * @param sequence1 the first sequence to test * @param sequence2 the second sequence to test * * @return a true if the first list is a subsequence of the other */ public static  boolean subSequence(List sequence1, List sequence2) { boolean result = false; // IMPLEMENT THIS METHOD return result; } /** * getSequence - Get a sequence of words * @param prompt A string that prompts the user for the sequence of words. * @return A list of words. */ private static List getSequence(String prompt) { Scanner input; String inString = null; List sequence = new LinkedList(); try { input = new Scanner(System.in); System.out.println(prompt); inString = input.nextLine().trim(); Scanner theWords = new Scanner(inString); while(theWords.hasNext()) { sequence.add(theWords.next()); } } catch(Exception e) { System.out.println("There was an error with System.in"); System.out.println(e.getMessage()); System.out.println("Will use a sequence of size zero"); } return sequence; } public static void testSubSequence() { List s1, s2; System.out.println(); System.out.println("TEST CASES FOR THE SUBSEQUENCE METHOD"); s1 = new LinkedList(); s2 = new LinkedList(); s1.add("a"); s1.add("b"); s1.add("c"); System.out.println("s1 is " + s1); System.out.println("s2 is " + s2); testIsNotSubSequence(s1, s2, "s1", "s2"); testIsSubSequence(s2, s1, "s2", "s1"); s2.add("a"); s2.add("c"); s2.add("b"); System.out.println(); System.out.println("s1 is " + s1); System.out.println("s2 is " + s2); testIsNotSubSequence(s1, s2, "s1", "s2"); testIsNotSubSequence(s2, s1, "s2", "s1"); s2.add("c"); System.out.println(); System.out.println("s1 is " + s1); System.out.println("s2 is " + s2); testIsSubSequence(s1, s2, "s1", "s2"); testIsNotSubSequence(s2, s1, "s2", "s1"); System.out.println(); s1.add("a"); s1.add("b"); s1.add("c"); System.out.println("s1 is " + s1); System.out.println("s2 is " + s2); testIsNotSubSequence(s1, s2, "s1", "s2"); testIsSubSequence(s2, s1, "s2", "s1"); System.out.println(); s1.clear(); s1.add("a"); s1.add("b"); s1.add("a"); s1.add("c"); s2.clear(); s2.add("a"); s2.add("b"); s2.add("a"); s2.add("c"); System.out.println("s1 is " + s1); System.out.println("s2 is " + s2); testIsSubSequence(s1, s2, "s1", "s2"); testIsSubSequence(s2, s1, "s2", "s1"); } /** * A private method that will test the isSubSequence method with sequence1 * as the first sequence and sequence2 as the second sequence. It expects that * the correct answer should be true * @param sequence1 the first sequence * @param sequence2 the second sequence * @param name1 the name of the variable referencing sequence1 * @param name2 the name of the variable referencing sequence2 * * @return a list of words */ private static  void testIsSubSequence(List sequence1, List sequence2, String name1, String name2) { System.out.println("Testing if " + name1 + " is a subsequence of " + name2); if(subSequence(sequence1,sequence2)) { System.out.println(" Passes: returned true and " + name1 + " is a subsequence of " + name2); } else { System.out.println("**** Fails - returned false but " + name1 + " is a subsequence of " + name2); } } /** * A private method that will test the isSubSequence method with sequence1 * as the first sequence and sequence2 as the second sequence. It expects that * the correct answer should be false * @param sequence1 the first sequence * @param sequence2 the second sequence * @param name1 the name of the variable referencing sequence1 * @param name2 the name of the variable referencing sequence2 * * @return a list of words */ private static  void testIsNotSubSequence(List sequence1, List sequence2, String name1, String name2) { System.out.println("Testing if " + name1 + " is a subsequence of " + name2); if(!subSequence(sequence1,sequence2)) { System.out.println(" Passes: returned false and " + name1 + " is not a subsequence of " + name2); } else { System.out.println("**** Fails - returned true but " + name1 + " is not a subsequence of " + name2); } } }