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Freivalds' algorithm determines whether the matrices are equal for a chosen k value with a probability of failure less than 2^-k in O(kn^2).It is used to verify matrix multiplication.AlgorithmBegin Take matrix1(n*n), matrix2(n*n), matrix3(n*n) as input. // According to the algorithm we have to verify: // matrix1 × matrix2 = matrix3. 1) Choose vector a[n][1] randomly and uniformly in which component will be 0 or 1. 2) Compute matrix2 * a, matrix3 * a and then matrix1 * (matrix2 * a) for evaluating the expression, matrix1 * (matrix2 * a) - matrix3 * a. 3) ... Read More
The offset of the first element of the buffer inside the buffer array is obtained using the method arrayOffset() in the class java.nio.ShortBuffer. If the buffer backed by the array is read-only, then the ReadOnlyBufferException is thrown.A program that demonstrates this is given as follows −Example Live Demoimport java.nio.*; import java.util.*; public class Demo { public static void main(String[] args) { int n = 5; try { ShortBuffer buffer = ShortBuffer.allocate(5); buffer.put((short)12); buffer.put((short)91); buffer.put((short)25); ... Read More
A clock copy of the clock object can be obtained using the method withZone() in Clock Class in Java. This method is used on a clock object to obtain a clock copy. The withZone() method requires a single parameter i.e. the zone that is required to change the time zone. Also, it returns the clock copy of the clock object with the required time zone.A program that demonstrates this is given as follows −Example Live Demoimport java.time.*; public class Demo { public static void main(String[] args) { Clock c1 = Clock.systemDefaultZone(); ZoneId zone = ... Read More
Let us first see what we need to work with JavaTuples. To work with Triplet class in JavaTuples, you need to import the following package −import org.javatuples.Triplet;Note − Steps to download and run JavaTuples program If you are using Eclipse IDE to run Triplet Class in JavaTuples, then Right Click Project -> Properties -> Java Build Path -> Add External Jars and upload the downloaded JavaTuples jar file.The following is an example −Exampleimport org.javatuples.Triplet; public class Demo { public static void main(String[] args) { Triplet < String, String, String > t = new Triplet < String, String, String > ... Read More
To get the server_id, use the system defined variable @@server_id. You cannot use only a single @ as user defined variable for server_id.The syntax is as followsSELECT@@ server_idAs an alternate, you can use SHOW VARIABLES command.The syntax is as followsSHOW VARIABLES LIKE ‘server_id’;Case 1The query is as followsmysql> SELECT @@server_id as SERVER_ID;The following is the output+-----------+ | SERVER_ID | +-----------+ | 1 | +-----------+ 1 row in set (0.00 sec)Case 2The query is as followsmysql> show variables like 'server_id';The following is the output+---------------+-------+ | Variable_name | Value | +---------------+-------+ | server_id | ... Read More
The second of minute for a particular LocalDateTime can be obtained using the getSecond() method in the LocalDateTime class in Java. This method requires no parameters and it returns the second of the minute in the range of 0 to 59.A program that demonstrates this is given as follows −Example Live Demoimport java.time.*; public class Demo { public static void main(String[] args) { LocalDateTime ldt = LocalDateTime.parse("2019-02-18T23:15:30"); System.out.println("The LocalDateTime is: " + ldt); System.out.println("The second is: " + ldt.getSecond()); } }OutputThe LocalDateTime is: 2019-02-18T23:15:30 The second is: 30Now let us ... Read More
The remainingCapacity() method of the ArrayBlockingQueue class in Java is used to return the number of additional elements that the queue can adopt without blocking.The syntax is as followsint remainingCapacity()To work with ArrayBlockingQueue class, you need to import the following packageimport java.util.concurrent.ArrayBlockingQueue;The following is an example to implement remainingCapacity() method of Java ArrayBlockingQueue classExample Live Demoimport java.util.concurrent.ArrayBlockingQueue; public class Demo { public static void main(String[] args) throws InterruptedException { ArrayBlockingQueue q = new ArrayBlockingQueue(10); q.add(120); q.add(400); q.add(450); q.add(500); System.out.println("ArrayBlockingQueue = " + ... Read More
Apache Derby is a Relational Database Management System which is fully based on (written/implemented in) Java programming language. It is an open source database developed by Apache Software Foundation.Installing derby:Follow the steps given below to install derby:Visit the home page of Apache Derby home page https://db.apache.org/derby/. Click the Download tab.Select and click on the link of the latest version of Apache Derby.On clicking the selected link, you will be redirected to the Distributions page of apache derby. If you observe here, derby provides distributions namely, db-derby-bin, db-derbylib.zip, db-derby-lib-debug.zip, and db-derby-src.zip.Download the db-derby-bin folder. Copy its contents to a separate folder ... Read More
This example demonstrates about Uninstall APKs programmaticallyStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml. In the above code, we have taken a text view.Step 3 − Add the following code to src/MainActivity.javapackage com.example.myapplication; import android.app.Activity; import android.content.Intent; import android.content.SharedPreferences; import android.net.Uri; import android.os.Bundle; import android.support.v4.content.pm.ShortcutInfoCompat; import android.support.v4.content.pm.ShortcutManagerCompat; import android.support.v4.graphics.drawable.IconCompat; import android.view.View; import android.widget.TextView; import android.widget.Toast; public class MainActivity extends Activity { private static final String PREF_KEY_SHORTCUT_ADDED = "Sairam"; TextView ... Read More
The count(*) returns all rows whether column contains null value or not while count(columnName) returns the number of rows except null rows.Let us first create a table.Following is the querymysql> create table ifNotNullDemo -> ( -> Name varchar(20) -> ); Query OK, 0 rows affected (0.54 sec)Following is the query to insert some records in the table using insert command:mysql> insert into ifNotNullDemo values('Chris'); Query OK, 1 row affected (0.15 sec) mysql> insert into ifNotNullDemo values(''); Query OK, 1 row affected (0.13 sec) mysql> insert into ifNotNullDemo values('Robert'); Query OK, 1 row affected (0.24 sec) ... Read More