toArray Method of CopyOnWriteArrayList in Java

Smita Kapse
Updated on 30-Jul-2019 22:30:25

107 Views

The toArray() method is used to return an array containing all the elements in this list in proper sequence.The syntax is as follows −Object[] toArray()To work with CopyOnWriteArrayList class, you need to import the following package −import java.util.concurrent.CopyOnWriteArrayList;The following is an example to implement CopyOnWriteArrayList class toArray() method in Java−Example Live Demoimport java.util.Arrays; import java.util.concurrent.CopyOnWriteArrayList; public class Demo { public static void main(String[] args) { CopyOnWriteArrayList arrList = new CopyOnWriteArrayList(); arrList.add(220); arrList.add(250); arrList.add(400); ... Read More

Get a Particular Element from MongoDB Array

Nishtha Thakur
Updated on 30-Jul-2019 22:30:25

229 Views

You can use the aggregate framework to get a particular element from the MongoDB array. To understand the concept, let us create a collection with the document. The query to create a collection with the document is as follows −> db.getParticularElement.insertOne({"InstructorName":"Larry", "InstructorTechnicalSubject":["Java", "C", "C++", "MongoDB", "MySQL", "SQL Server"]}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c7ee027559dd2396bcfbfb1") }Display all documents from a collection with the help of find() method. The query is as follows −> db.getParticularElement.find().pretty();The following is the output −{    "_id" : ObjectId("5c7ee027559dd2396bcfbfb1"),    "InstructorName" : "Larry",    "InstructorTechnicalSubject" : [       "Java",       ... Read More

Order By a Function of Two Columns in a Single MySQL Query

Ankith Reddy
Updated on 30-Jul-2019 22:30:25

139 Views

Let us first create a tablemysql> create table orderByAFunctionDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> FirstNumber int,    -> SecodNumber int    -> ); Query OK, 0 rows affected (0.44 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into orderByAFunctionDemo(FirstNumber, SecodNumber) values(10, 4); Query OK, 1 row affected (0.11 sec) mysql> insert into orderByAFunctionDemo(FirstNumber, SecodNumber) values(45, 78); Query OK, 1 row affected (0.17 sec) mysql> insert into orderByAFunctionDemo(FirstNumber, SecodNumber) values(23, 10); Query OK, 1 row affected (0.12 sec) mysql> insert into orderByAFunctionDemo(FirstNumber, SecodNumber) values(67, ... Read More

Find Size of the Largest Independent Set (LIS) in a Binary Tree

Samual Sam
Updated on 30-Jul-2019 22:30:25

185 Views

This is a C++ Program to Find Size of the Largest Independent Set (LIS) in a Given a Binary Tree.AlgorithmBegin.    Create a structure n to declare data d, a left child pointer l and a right child pointer r.    Call a function max() to return maximum between two integers. Create a function LIS() to return the    size of the largest independent set in a given binary tree.    Calculate size excluding the current node    int size_excl = LIS(root->l) + LIS(root->r)    Calculate size including the current node    int size_incl = 1;    if (root->l)   ... Read More

C++ Program to Implement Network Flow Problem

Daniol Thomas
Updated on 30-Jul-2019 22:30:25

621 Views

This is a C++ Program to implement Network_Flow problem using Ford Fulkerson algorithm.Algorithms:Begin    function bfs() returns true if there is path from source s to sink t in    the residual graph which indicates additional possible flow in the graph. End Begin    function fordfulkarson() return maximum flow in given graph:    A) initiate flow as 0.    B) If there is an augmenting path from source to sink, add the path to flow.    C) Return flow. EndExample Code#include #include #include #include #define n 7 using namespace std; bool bfs(int g[n][n], int s, int ... Read More

Retrieve Documents Whose Values End with a Particular Character in MongoDB

Arjun Thakur
Updated on 30-Jul-2019 22:30:25

2K+ Views

Following is the syntax to retrieve the documents whose values end with a particular character in MongoDBdb.yourCollectionName.find({yourFieldName: {$regex: "yourEndingCharacter$"}}).pretty();Let us first create a collection with documents>db.retrieveDocumentsWithEndsWithParticularCharacterDemo.insertOne({"StudentName":"Adam", "StudentAge":25, "StudentCountryName":"LAOS"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9c45b32d66697741252456") } >db.retrieveDocumentsWithEndsWithParticularCharacterDemo.insertOne({"StudentName":"Sam", "StudentAge":24, "StudentCountryName":"ANGOLA"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9c45c02d66697741252457") } >db.retrieveDocumentsWithEndsWithParticularCharacterDemo.insertOne({"StudentName":"Robert", "StudentAge":21, "StudentCountryName":"AUS"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9c45cb2d66697741252458") } >db.retrieveDocumentsWithEndsWithParticularCharacterDemo.insertOne({"StudentName":"Chris", "StudentAge":20, "StudentCountryName":"UK"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9c45d92d66697741252459") } >db.retrieveDocumentsWithEndsWithParticularCharacterDemo.insertOne({"StudentName":"Larry", "StudentAge":23, "StudentCountryName":"US"}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c9c45eb2d6669774125245a") }Following is the query to display all documents from a collection ... Read More

Sort a Subset of Array Elements in Java

karthikeya Boyini
Updated on 30-Jul-2019 22:30:25

344 Views

Let us first create a string array −String[] strArr = new String[] { "r", "p", "v", "y", "s", "q" };Now, use Arrays.sort() to get the subset. Use the following to sort only from the index range 2 to 6.Arrays.sort(strArr, 2, 6);Example Live Demoimport java.util.Arrays; public class Demo {    public static void main(String[] args) {       String[] strArr = new String[] { "r", "p", "v", "y", "s", "q" };       Arrays.sort(strArr, 2, 6);       System.out.println("Sorted subset of array elements from index 2 to 6...");       for (int a = 0; a < strArr.length; ... Read More

Compound Literals in C

Smita Kapse
Updated on 30-Jul-2019 22:30:25

616 Views

In this section we will see what is the compound literals in C. The compound literals are introduced in C99 standard in C. Using this feature, it can create unnamed objects. In the following example we will see how to use compound literal to generate object without any name.Example#include struct point {    int x;    int y; }; void display_point(struct point pt) {    printf("(%d,%d)", pt.x, pt.y); } main() {    display_point((struct point) {10, 20}); }Output(10,20)

Transpose a Matrix in Python

Arjun Thakur
Updated on 30-Jul-2019 22:30:25

3K+ Views

Transpose a matrix means we’re turning its columns into its rows. Let’s understand it by an example what if looks like after the transpose.Let’s say you have original matrix something like -x = [[1, 2][3, 4][5, 6]]In above matrix “x” we have two columns, containing 1, 3, 5 and 2, 4, 6.So when we transpose above matrix “x”, the columns becomes the rows. So the transposed version of the matrix above would look something like -x1 = [[1, 3, 5][2, 4, 6]]So the we have another matrix ‘x1’, which is organized differently with different values in different places.Below are couple ... Read More

Instruction Cycle in 8085 Microprocessor

Chandu yadav
Updated on 30-Jul-2019 22:30:25

5K+ Views

The Program and data which are stored in the memory, are used externally to the microprocessor for executing the complete instruction cycle. Thus to execute a complete instruction of the program, the following steps should be performed by the 8085 microprocessor.Fetching the opcode from the memory;Decoding the opcode to identify the specific set of instructions;Fetching the remaining Bytes left for the instruction, if the instruction length is of 2 Bytes or 3 Bytes;Executing the complete instruction procedure.The given steps altogether constitute the complete instruction cycle. These above mentioned steps are described in detail later. The above instructions are assumed by ... Read More

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