From e670b5c49c5dc9c7c7f0eaad37d50bf2246f0d85 Mon Sep 17 00:00:00 2001
From: afroneth <knjh30@gmail.com>
Date: Sat, 5 Sep 2020 23:16:17 +0800
Subject: [PATCH] Add C - Better Search

---
 data/duke.txt                  |  3 ++
 src/main/java/FindCommand.java | 54 +++++++++++++++++++++++-----------
 src/main/java/Main.java        |  1 -
 src/main/java/Parser.java      |  8 +++--
 4 files changed, 45 insertions(+), 21 deletions(-)

diff --git a/data/duke.txt b/data/duke.txt
index f8ea583f0f..2c1e6b841d 100644
--- a/data/duke.txt
+++ b/data/duke.txt
@@ -2,3 +2,6 @@ T|1|sleep
 E|0|project meeting|30/3/2019 1412
 D|0|concert preparation|14/12/2020 1312
 D|1|project|12/12/2012 1212
+T|0|eat mala project
+E|0|malay project|12/12/2012 1212
+T|0|meet someone
diff --git a/src/main/java/FindCommand.java b/src/main/java/FindCommand.java
index 8cd19d9e0d..929974285f 100644
--- a/src/main/java/FindCommand.java
+++ b/src/main/java/FindCommand.java
@@ -1,22 +1,19 @@
-/**
- * Implements methods for FindCommand.
- */
 public class FindCommand extends Command {
     protected boolean isExit;
-    private String keyword;
+    private String[] searchTerms;
 
     /**
      * Instantiates FindCommand object.
-     * @param keyword Keyword used to find matching tasks.
+     * @param searchTerms Keyword to find.
      */
-    public FindCommand(String keyword) {
-        this.keyword = keyword;
+    public FindCommand(String[] searchTerms) {
+        this.searchTerms = searchTerms;
     }
 
     /**
      * Runs command to handle find command.
      *
-     * @param arrayOfTasks Array of tasks that we have parsed.
+     * @param arrayOfTasks Array of Tasks that we have parsed.
      * @param ui Ui object to aid in program execution.
      * @param storage Storage object to aid in program execution.
      * @return Response object
@@ -24,21 +21,23 @@ public FindCommand(String keyword) {
     public Response runCommand(TaskList arrayOfTasks, Ui ui, Storage storage) {
         assert arrayOfTasks != null || ui != null || storage != null
                 : "arrayOfTasks, Ui and Storage objects cannot be null";
+
         TaskList matchedTasksList = new TaskList();
         int arraySize = arrayOfTasks.taskArraySize();
         int index = 0;
         while (index < arraySize) {
             Task matchedTask = arrayOfTasks.get(index);
             String[] splitElements = matchedTask.description.split(" ");
-            int numOfElements = splitElements.length;
             boolean isMatching = false;
-            int secondIndex = 0;
-            while (secondIndex < numOfElements) {
-                if (splitElements[secondIndex].strip().equalsIgnoreCase(keyword)) {
-                    isMatching = true;
-                    break;
-                }
-                secondIndex++;
+
+            String delimiter = "";
+            String keyword = String.join(delimiter, searchTerms);
+            String taskInList = String.join(delimiter, splitElements);
+            int keywordLength = keyword.length();
+            int taskLength = taskInList.length();
+
+            if (isSubSequence(keyword, taskInList, keywordLength, taskLength)) {
+                isMatching = true;
             }
 
             if (!isMatching) {
@@ -57,7 +56,7 @@ public Response runCommand(TaskList arrayOfTasks, Ui ui, Storage storage) {
     }
 
     /**
-     * Checks if the program has to exit Duke.
+     * Since this is not a exit command, it does not signal the program to exit.
      *
      * @return exitCheck as False
      */
@@ -65,4 +64,25 @@ public boolean exitChecker() {
         isExit = false;
         return isExit;
     }
+
+    static boolean isSubSequence(String keyword, String task, int keywordLength, int taskLength) {
+        if (taskLength == 0) {
+            return false;
+        }
+
+        if (keywordLength == 0) {
+            return true;
+        }
+
+        char keywordCharacter = keyword.charAt(keywordLength - 1);
+        char taskCharacter = task.charAt(taskLength - 1);
+
+        // Checks if last characters of two strings matches
+        if (keywordCharacter == taskCharacter) {
+            return isSubSequence(keyword, task, keywordLength - 1, taskLength - 1);
+        }
+
+        // Recurse if last characters do not match
+        return isSubSequence(keyword, task, keywordLength, taskLength - 1);
+    }
 }
diff --git a/src/main/java/Main.java b/src/main/java/Main.java
index 99bedd9e12..30e66bcd97 100644
--- a/src/main/java/Main.java
+++ b/src/main/java/Main.java
@@ -6,7 +6,6 @@
 import javafx.scene.layout.AnchorPane;
 import javafx.stage.Stage;
 
-
 /**
  * A GUI for Duke using FXML.
  */
diff --git a/src/main/java/Parser.java b/src/main/java/Parser.java
index e3cdd793cb..94affbbf27 100644
--- a/src/main/java/Parser.java
+++ b/src/main/java/Parser.java
@@ -1,3 +1,5 @@
+import java.util.Arrays;
+
 /**
  *  Parses user input.
  */
@@ -231,9 +233,9 @@ private static FindCommand processFindCommand(String inputLine) throws DukeExcep
         if (numOfTokens < 2) {
             throw new DukeException("Please specific keyword to locate task. Eg. find book");
         }
-        String tempString = inputLine.split("find")[1];
-        String strippedKeyword = tempString.strip();
-        return new FindCommand(strippedKeyword);
+
+        String[] copiedArray = Arrays.copyOfRange(arrayOfElements, 1, arrayOfElements.length);
+        return new FindCommand(copiedArray);
     }
 
     private static HelpCommand processHelpCommand() {