Sudoku Solver : Solve any level of Sudoku

Sudoku Solver :
This is implemented by simple back-tracking algorithm (Backtracking Ref) in Javacript.

Simple steps to solve your Sudoku :
     1. Download the file  Sudoku Solver
     2. Make sure the downloaded file should be save as .html  file, else rename it to <filename>.html
     3. Open downloaded file in browser

Algorithm :
Input : A 2D 9x9 array (arr) with having valid and solvable input values.
            Valid - No number (1-9) is repeated in a same row, same column or same 3x3 box.
            Solvable - Even though the input is valid, but there is a chance of not having the solution for a                               particular input if that is randomly generated.

boolean solveSudoku(arr[9][9])
               Find an EMPTY cell (r, c) from the array 
               If no EMPTY cell found then
                         return TRUE ; // i.e the array is filled i.e. solved
               else
                         for num from 1 to 9
                                 check if arr[r][c] is SAFE to put num
                                 if SAFE then
                                            arr[r][c] = num; //update cell with num, consider this is a part of the goal
                                            // call recursively solveSudoku(arr) to solve next EMPTY cell
                                            result = solveSudoku(arr) 
                                            if result is FALSE then   // No solution  exist with arr[r][c] = num 
                                                      arr[r][c] = 0;  // Revert back the considered solution
                                            else
                                                      return TRUE; // We reached at the goal by taking arr[r][c] =num
                       end for
                       return FALSE;   // No solution exists, since no number from 1 to 9 can be placed at(r,c)

For SAFE checking :
boolean isSafe(arr[9][9], roe, col, num)
        if num is present in same row or same column or same inner 3x3 box then
                 return FALSE
        else
                return TRUE


Get Source Code here.

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Text to Speech in Java

Converting text-to-speech is very simple, just by using FreeTTS library.

Include library by maven dependency :

<dependency>

<groupId>org.mobicents.external.freetts</groupId>

<artifactId>freetts</artifactId>

<version>1.0</version>

</dependency>

OR

Download library (jar file) from here and include into project directly.

How to use FreeTTS API ?

Step - 1 : Get the instance of com.sun.speech.freetts.VoiceManager class.

               VoiceManager provides access to all voices available in FreeTTS

               VoiceManager voiceManager = VoiceManager.getInstance();

Step - 2 : Get com.sun.speech.freetts.Voice instance using voiceManager by supplying the voice name

               Voice voice = voiceManager.getVoice("kevin16");

               Here "kevin16" is one of the voice name available in FreeTTS library.

               You can also get all available voice names like below :

               

              Voice voices1[] = voiceManager.getVoices();  

              System.out.println("Available Voices");

              for (int i = 0; i < voices1.length; i++)

            System.out.println(voices1[i].getName());

Step - 3 : Set voice rate (i.e no of words per minute)

              voice.setRate(120);

Step - 4 : call speak( ) method by providing the text to speech

              voice.speak("<text to speech>");

              This speak( ) is overloaded to support various types of inputs like text, inputStream etc.

              You can also read a file by providing the fileInputStream as below : 

              FileInputStream fileInputStream = new FileInputStream("d:/ttsInput.txt");

              voice.speak(fileInputStream);

Here is the complete code to convert a text file to speech : 

import com.sun.speech.freetts.Voice;

import com.sun.speech.freetts.VoiceManager;

import java.io.FileInputStream;

public class TextToSpeech {

    private static final String voiceName = "kevin16"; // this is one of the voice name available in default

    private static void doSpeak() {

        try {

            VoiceManager voiceManager = VoiceManager.getInstance();

            Voice voice = voiceManager.getVoice(voiceName);

            if (voice != null) {

                voice.allocate();

                // Set 120 words per minute

                voice.setRate(120);

                FileInputStream fileInputStream = new                                                                FileInputStream("d:/ttsInput.txt");

                voice.speak(fileInputStream);

                voice.deallocate();

            } else {

                System.out.println("No Voice Available");

            }

        } catch (Exception e) {

            e.printStackTrace();

        }

    }

    public static void main(String[] args){

        doSpeak();

    }

}

Here is a demonstration of a Speaking Alarm Clock application using this FreeTTS library.

Functionalities of application : 

1. class AlarmClock : This class creates the alarm clock UI using Java Swing API, having feature to set alarm for a specific time and triggers the TimeSpeaker to speak the time on the time for which alarm is set.

2. class TimeSpeaker : This class converts any time into word form

                            e.g  05:15 -> quarter past five

                                  03:30 -> half past three

                                  11:40 -> twenty minutes to twelve

3. class TextToSpeech : This is the class responsible of converting text to speech using freetts (Free Text To Speech) library

Download OR fork complete project from here .

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