import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.io.*;
import javax.imageio.ImageIO;
import java.awt.Color;
import java.util.*;
class Circle {
public int x, y; // the coordinates of the center of the circle
public int radius; // the radius of the circle
public int red, green, blue; // the RGB values of the color of the circle
public int alpha; // the alpha value of the color
public int time; // the time when this circle was added to the member to which it belongs
public boolean isPointInside(int i, int j) {
return (this.x - i) * (this.x - i) + (this.y - j) * (this.y - j) <= this.radius * this.radius;
}
public Circle() {
}
public Circle(Circle other) {
this.x = other.x ;
this.y = other.y ;
this.red = other.red ;
this.green = other.green ;
this.blue = other.blue ;
this.alpha = other.alpha ;
this.time = other.time ;
this.radius = other.radius;
}
}
class Genotype {
public Circle circles[] = new Circle[GeneticAlgorithm.circleCount]; // each member of population contains a list of circles
public int count; // stores the number of circles in the present member of population
public int bg_red, bg_green, bg_blue; // the RGB values of the background
public int bg_alpha; // the alpha value of the background
public double fitness;
public double cfitness;
public double rfitness;
public Genotype() {
for(int i = 0 ; i < circles.length ; i++)
this.circles[i] = new Circle();
}
public Genotype(Genotype other) {
for(int i = 0 ; i < circles.length ; i++)
this.circles[i] = new Circle(other.circles[i]);
this.count = other.count ;
this.bg_red = other.bg_red ;
this.bg_green = other.bg_green ;
this.bg_blue = other.bg_blue ;
this.bg_alpha = other.bg_alpha ;
this.fitness = other.fitness ;
this.cfitness = other.cfitness ;
this.rfitness = other.rfitness ;
}
public Color getColorOfPoint(int i, int j) {
TreeMap <Integer, Circle> treemap = new TreeMap <Integer, Circle> ();
for(int k = 0 ; k < circles.length ; ++k) {
if(circles[k].isPointInside(i, j))
treemap.put(circles[k].time, circles[k]);
}
// Color color = new Color(bg_red, bg_green, bg_blue);
Iterator it = treemap.entrySet().iterator();
// int entries = 0;
// int sum_r = 0, sum_g = 0, sum_b=0;
double color_red = bg_red, color_green = bg_green, color_blue = bg_blue, color_alpha = bg_alpha;
while(it.hasNext()) {
// entries ++;
Map.Entry entry = (Map.Entry)it.next();
Circle c = (Circle)entry.getValue();
double t = (double)(c.alpha/255.0) ;
// double new_bg_alpha = (double)(color.getAlpha()/255.0);
double new_alpha=(double)(t + (1.0 - t) * color_alpha);
// System.out.println("red = "+Float.toString((double)((t * c.red + (1.0 - t) * color.getRed()*new_bg_alpha )/new_alpha)));
// int bg_red = color.getRed();
// int bg_green = color.getGreen();
// int bg_blue = color.getBlue();
// sum_r += c.red;
// sum_g += c.green;
// sum_b += c.blue;
color_red = (t*c.red + (1.0-t)*color_red*color_alpha)/new_alpha;
color_green = (t*c.green + (1.0-t)*color_green*color_alpha)/new_alpha;
color_blue = (t*c.blue + (1.0-t)*color_blue*color_alpha)/new_alpha;
color_alpha = new_alpha;
// color = new Color((int)((t * c.red + (1.0 - t) *bg_red *new_bg_alpha )/new_alpha), (int)((t * c.green + (1.0 - t) * bg_green*new_bg_alpha)/new_alpha), (int)((t * c.blue + (1.0 - t) * bg_blue*new_bg_alpha)/new_alpha),(int)(new_alpha*255.0) );
};
Color color = new Color((int)color_red, (int)color_green, (int)color_blue, (int)(255*color_alpha) );
// if(entries !=0)
// {
// sum_r = (int)(sum_r/(entries*1.0));
// sum_g = (int)(sum_g/(entries*1.0));
// sum_b = (int)(sum_b/(entries*1.0));
// color = new Color(sum_r, sum_g, sum_b);
// }
return color;
}
public int abs(int diff)
{
if(diff < 0) return -1*diff;
return diff;
}
public int idnt(int diff)
{
if(diff == 0)
return 1;
return 0;
}
public double getFitness(int[][] result) {
double ans = 0;
for(int i = 0 ; i < result.length ; i++) {
for(int j = 0 ; j < result[0].length ; j++) {
Color m = getColorOfPoint(i, j);
Color n = new Color(result[i][j]);
double moda = Math.sqrt(m.getRed()*m.getRed() + m.getGreen()*m.getGreen()+m.getBlue()*m.getBlue());
double modb = Math.sqrt(n.getRed()*n.getRed() + n.getGreen()*n.getGreen()+n.getBlue()*n.getBlue());
// System.out.println(((m.getRed()*n.getRed())+(m.getGreen()*n.getGreen())+(m.getBlue()+n.getBlue()))/(moda*modb));
// ans += ((m.getRed()*n.getRed())+(m.getGreen()*n.getGreen())+(m.getBlue()+n.getBlue()))/((1+moda)*(modb+1));
ans += ((Math.pow(2,abs(m.getRed() - n.getRed())/255.0) + Math.pow(2,abs(m.getGreen() - n.getGreen())/255.0) + Math.pow(2,abs(m.getBlue() - n.getBlue())/255.0)) )/6.0;
//ans += abs((m.getRed() - n.getRed())) + abs((m.getGreen() - n.getGreen())) + abs((m.getBlue() - n.getBlue()));
//ans += idnt((m.getRed() - n.getRed())) + idnt((m.getGreen() - n.getGreen())) + idnt((m.getBlue() - n.getBlue()));
}
}
// System.out.println(ans);
this.fitness = 100000.0/ans;
return this.fitness;
}
public void print(){
//for(int i=0;i<GeneticAlgorithm.circleCount;++i)
for(int i=0;i<-1;++i)
{
Circle temp = new Circle(circles[i]);
//System.out.println("x = "+Integer.toString(temp.x)+" |y = "+Integer.toString(temp.y)+" |radius = "+Integer.toString(temp.radius) + " |red= "+ Integer.toString(temp.red) + " |green = "+ Integer.toString(temp.green)+" |blue= "+Integer.toString(temp.blue)+" |alpha= "+Float.toString(temp.alpha)+" |time= "+Integer.toString(temp.time));
}
}
}
public class GeneticAlgorithm {
private static int[][] convertTo2D(BufferedImage image) {
final byte[] pixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
//Raster raster = image.getRaster();
final int width = image.getWidth();
final int height = image.getHeight();
int[][] result = new int[height][width];
if (image.getAlphaRaster() != null) {
System.out.println("You are screwed");
final int pixelLength = 3;
for (int pixel = 0, row = 0, col = 0; pixel < pixels.length; pixel += pixelLength) {
int argb = 0;
//argb += -16777216; // 255 alpha
//argb += (((int) pixels[pixel] & 0xff) << 24); // alpha
argb += ((int) pixels[pixel + 1] & 0xff); // blue
argb += (((int) pixels[pixel + 2] & 0xff) << 8); // green
argb += (((int) pixels[pixel + 3] & 0xff) << 16); // red
result[row][col] = argb;
col++;
if (col == width) {
col = 0;
row++;
}
}
}
else {
final int pixelLength = 3;
for (int pixel = 0, row = 0, col = 0; pixel < pixels.length; pixel += pixelLength) {
int argb = 0;
//argb += -16777216; // 255 alpha
argb += ((int) pixels[pixel] & 0xff); // blue
argb += (((int) pixels[pixel + 1] & 0xff) << 8); // green
argb += (((int) pixels[pixel + 2] & 0xff) << 16); // red
result[row][col] = argb;
col++;
if (col == width) {
col = 0;
row++;
}
}
}
return result;
}
public static void convertColorArrayToImage(int[][] color, int generation, int member, String imageName, String directory) {
String curr = imageName ;
// if(generation < 10)
// curr = curr + "000" ;
// else if(generation < 100)
// curr = curr + "00" ;
// else if(generation < 1000)
// curr = curr + "0" ;
String path = directory+curr +"-"+ Integer.toString(generation) + ".jpg";
//String path = "result" + Integer.toString(generation) + ".jpg";
BufferedImage image = new BufferedImage(color[0].length, color.length, BufferedImage.TYPE_INT_RGB);
for(int i = 0; i < color.length; i++)
for(int j = 0; j < color[0].length; j++)
image.setRGB(j, i, color[i][j]);
File ImageFile = new File(path);
try {
ImageIO.write(image, "jpg", ImageFile);
}
catch(IOException e) {
e.printStackTrace();
}
}
public static int POPSIZE = 15;
public static int MAXGENS = 150000;
public static double PXOVER = 0.8;
public static double PMUTATION = 0.1;
public static Genotype population[];
public static Genotype newpopulation[];
public static int row, col;
public static int circleCount = 50;
public static int[][] result;
public static int RADIUSLIMIT=175;
public static double PMUTATIONCOLOR = .2;
public static void crossover() {
int mem;
int one = 0;
int first = 0;
double x;
for(mem = 0; mem < POPSIZE; ++mem) {
Random randomGenerator = new Random();
x = (randomGenerator.nextInt(1000)) / 1000.0;
if(x < PXOVER) {
++first;
if(first % 2 == 0)
Xover(one, mem);
else
one = mem;
}
}
}
public static void elitist() {
int i;
double best;
int best_mem = 0;
double worst;
int worst_mem = 0;
best = population[0].fitness;
worst = population[0].fitness;
for(i = 0; i < POPSIZE ; ++i) {
if(population[i].fitness > best) {
best = population[i].fitness;
best_mem = i ;
}
if(population[i].fitness < worst) {
worst = population[i].fitness ;
worst_mem = i ;
}
}
//
// If the best individual from the new population is better than
// the best individual from the previous population, then
// copy the best from the new population; else replace the
// worst individual from the current population with the
// best one from the previous generation
//
if(best >= population[POPSIZE].fitness)
population[POPSIZE] = new Genotype(population[best_mem]);
else
{
population[worst_mem] = new Genotype(population[POPSIZE]);
}
}
public static void evaluate() {
//System.out.println("inside evaluate");
for(int member = 0; member < POPSIZE; member++)
population[member].getFitness(result);
}
public static void initialize() {
population = new Genotype[POPSIZE + 1];
newpopulation = new Genotype[POPSIZE + 1];
Random randomGenerator = new Random();
for(int i = 0 ; i <= POPSIZE ; i++) {
population[i] = new Genotype();
newpopulation[i] = new Genotype();
population[i].count = circleCount;
for(int j = 0 ; j < circleCount ; j++) {
population[i].circles[j].x = new Integer(randomGenerator.nextInt(row));
population[i].circles[j].y = new Integer(randomGenerator.nextInt(col));
population[i].circles[j].blue = new Integer(randomGenerator.nextInt(255));
population[i].circles[j].red = new Integer(randomGenerator.nextInt(255));
population[i].circles[j].green = new Integer(randomGenerator.nextInt(255));
//System.out.println(i + "\t" + j + "\t" + population[i].circles[j].red + "\t" + population[i].circles[j].green + "\t" + population[i].circles[j].red);
population[i].circles[j].alpha = new Integer(randomGenerator.nextInt(255));
population[i].circles[j].radius = new Integer(randomGenerator.nextInt(RADIUSLIMIT));
population[i].circles[j].time = new Integer(randomGenerator.nextInt(10000));
//System.out.println("Radius = " + population[i].circles[j].radius);
}
population[i].bg_red =255;
population[i].bg_green = 255;
population[i].bg_blue = 255;
population[i].bg_alpha = 0;
}
//System.out.println("inside initialize");
//population[POPSIZE].print();
}
public static void keep_the_best() {
int cur_best;
int mem;
int i;
cur_best = 0;
for(mem = 1; mem < POPSIZE; mem++) {
if(population[mem].fitness > population[cur_best].fitness)
cur_best = mem;
}
//
// Once the best member in the population is found, copy the genes.
//
population[POPSIZE] = new Genotype(population[cur_best]);
}
public static void mutate() {
for(int i = 0; i < POPSIZE; i++) {
Random randomGenerator = new Random();
for(int j = 0 ; j<circleCount;++j)
{
double x = randomGenerator.nextInt(10000) / 10000.0;
//System.out.println("x = " + x);
if(x<PMUTATION)
{
x= randomGenerator.nextInt(10000) / 10000.0;
if(x < PMUTATIONCOLOR) {
//int j = new Integer(randomGenerator.nextInt(circleCount));
//System.out.println("Mutating");
//System.out.println("Value = " + population[i].circles[j].x);
population[i].circles[j].x = new Integer(randomGenerator.nextInt(row));
}
x= randomGenerator.nextInt(10000) / 10000.0;
if(x < PMUTATIONCOLOR) {
//System.out.println("Value = " + population[i].circles[j].x);
population[i].circles[j].y = new Integer(randomGenerator.nextInt(col));
}
x= randomGenerator.nextInt(10000) / 10000.0;
if(x < PMUTATIONCOLOR) {
population[i].circles[j].red = new Integer(randomGenerator.nextInt(255));
}
x= randomGenerator.nextInt(10000) / 10000.0;
if(x < PMUTATIONCOLOR) {
population[i].circles[j].green = new Integer(randomGenerator.nextInt(255));
}
x= randomGenerator.nextInt(10000) / 10000.0;
if(x < PMUTATIONCOLOR) {
population[i].circles[j].blue = new Integer(randomGenerator.nextInt(255));
}
x= randomGenerator.nextInt(10000) / 10000.0;
if(x < PMUTATIONCOLOR) {
population[i].circles[j].alpha = new Integer(randomGenerator.nextInt(255));
}
x= randomGenerator.nextInt(10000) / 10000.0;
if(x < PMUTATION) {
population[i].circles[j].radius = new Integer(randomGenerator.nextInt(RADIUSLIMIT));
}
x= randomGenerator.nextInt(10000) / 10000.0;
if(x < PMUTATION) {
population[i].circles[j].time = new Integer(randomGenerator.nextInt(10000));
}
}
}
}
//population[i].bg_red = randomGenerator.nextInt(255);
//population[i].bg_green = randomGenerator.nextInt(255);
//population[i].bg_blue = randomGenerator.nextInt(255);
//population[i].bg_alpha = randomGenerator.nextInt(255);
}
public static double randval(double low, double high) {
Random randomGenerator = new Random();
return ((double)(randomGenerator.nextInt(1000)) / 1000.0) *(high - low) + low;
}
public static void selector() {
int i, j, mem;
double p, sum = 0.0;
//
// Find total fitness of the population
//
for(mem = 0; mem < POPSIZE; mem++)
sum = sum + population[mem].fitness;
//
// Calculate the relative fitness.
//
for(mem = 0; mem < POPSIZE; mem++)
population[mem].rfitness = population[mem].fitness / sum;
population[0].cfitness = population[0].rfitness;
//
// Calculate the cumulative fitness.
//
for(mem = 1; mem < POPSIZE; mem++)
population[mem].cfitness = population[mem-1].cfitness + population[mem].rfitness;
//
// Select survivors using cumulative fitness.
//
// System.out.println("cfitness values new");
// for(int z = 0 ; z < POPSIZE ; z++) {
// System.out.println(z + " : " + population[z].cfitness);
// }
for(i = 0; i < POPSIZE; i++)
{
Random randomGenerator = new Random();
p = (randomGenerator.nextInt(1000)) / 1000.0;
//System.out.println("p = " + p);
if(p < population[0].cfitness) {
// System.out.println(i + " Picking : " + 0);
newpopulation[i] = new Genotype(population[0]);
}
else
{
for(j = 0; j < POPSIZE; j++) {
if(p >= population[j].cfitness && p < population[j+1].cfitness) {
// System.out.println(i + " Picking : " + (j + 1));
newpopulation[i] = new Genotype(population[j+1]);
break ;
}
}
}
}
//
// Once a new population is created, copy it back
//
// System.out.println("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
// System.out.println("New pop");
// for(i = 0; i < POPSIZE; i++) {
// System.out.println(newpopulation[i].fitness);
// population[i] = new Genotype(newpopulation[i]);
// }
// System.out.println("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
}
public static void Xover(int one, int two) {
Genotype a = new Genotype(population[one]);
Genotype b = new Genotype(population[two]);
Random randomGenerator = new Random();
int k = randomGenerator.nextInt(a.circles.length);
for(int i = 0 ; i < k ; i++) {
Circle tmp = new Circle(a.circles[i]);
a.circles[i] = new Circle(b.circles[i]) ;
b.circles[i] = new Circle(tmp) ;
}
// int j=k; //two point crossover
// while(j==k) {j = randomGenerator.nextInt(a.circles.length);}
// for(int i = 0 ; i < j ; i++) {
// Circle tmp = new Circle(a.circles[i]);
// a.circles[i] = new Circle(b.circles[i]) ;
// b.circles[i] = new Circle(tmp) ;
// }
population[one] = new Genotype(a) ;
population[two] = new Genotype(b) ;
}
public static void main(String[] args) throws IOException {
PrintWriter writer = new PrintWriter(args[1]+"info.txt", "UTF-8");
writer.println("The first line");
writer.println("POPSIZE=" + Integer.toString(POPSIZE));
writer.println("MAXGENS=" + Integer.toString(MAXGENS));
writer.println("circleCount=" + Integer.toString(circleCount));
writer.println("RADIUSLIMIT=" + Integer.toString(RADIUSLIMIT));
writer.println("PXOVER=" + Double.toString(PXOVER));
writer.println("PMUTATION=" + Double.toString(PMUTATION));
writer.println("PMUTATIONCOLOR=" + Double.toString(PMUTATIONCOLOR));
// public static int MAXGENS = 300000;
// public static double PXOVER = 0.8;
// public static double PMUTATION = 0.2;
// public static Genotype population[];
// public static Genotype newpopulation[];
// public static int row, col;
// public static int circleCount = 30;
// public static int[][] result;
// public static int RADIUSLIMIT=70;
// public static double PMUTATIONCOLOR = .4;
// writer.println("The second line");
writer.close();
BufferedImage image = ImageIO.read(GeneticAlgorithm.class.getResource(args[0] + ".jpg")); //read the image into the image object
result = convertTo2D(image);
row = result.length;
col = result[0].length;
Genotype best = null;
initialize();
//System.out.println("After Initialize");
best = new Genotype(population[POPSIZE]);
best.print();
evaluate();
//System.out.println("After Evaluate");
best = new Genotype(population[POPSIZE]);
best.print();
keep_the_best();
//System.out.println("After Keep_the_best");
best = new Genotype(population[POPSIZE]);
best.print();
double old_fitness = -1;
for(int generation = 0 ; generation < MAXGENS ; generation++) {
selector();
//System.out.println("After Selector");
//best = new Genotype(population[POPSIZE]);
//best.print();
// for(int i = 0 ; i <= POPSIZE ; i++)
// population[i].getFitness(result);
crossover();
//System.out.println("After Crossover");
// best = new Genotype(population[POPSIZE]);
//best.print();
// for(int i = 0 ; i <= POPSIZE ; i++)
// population[i].getFitness(result);
mutate();
//System.out.println("After Mutate");
//best = new Genotype(population[POPSIZE]);
//best.print();
// for(int i = 0 ; i <= POPSIZE ; i++)
// population[i].getFitness(result);
evaluate();
//System.out.println("After Evaluate");
// best = new Genotype(population[POPSIZE]);
//best.print();
// for(int i = 0 ; i <= POPSIZE ; i++)
// population[i].getFitness(result);
elitist();
//System.out.println("After Elitist");
best = new Genotype(population[POPSIZE]);
//best.print();
// for(int i = 0 ; i <= POPSIZE ; i++)
// population[i].getFitness(result);
//System.out.println("Generation " + generation);
// for(int i = 0 ; i < POPSIZE ; i++) {
// System.out.println(population[i].fitness);
// }
double new_fitness = best.fitness;
if(old_fitness!=new_fitness)
{
int answer[][] = new int[row][col];
for(int i = 0 ; i < row ; i++) {
for(int j = 0 ; j < col ; j++) {
Color c = population[POPSIZE].getColorOfPoint(i, j);
answer[i][j] = (c.getRed() << 16) | (c.getGreen() << 8) | c.getBlue();
//answer[i][j] = (c.getRed() << 24) | (c.getGreen() << 16) | (c.getBlue() << 8) | c.getAlpha();
}
}
convertColorArrayToImage(answer, generation,POPSIZE,args[0], args[1]);
}
old_fitness = new_fitness;
System.out.println(generation + "\t" + population[POPSIZE].fitness);
}
}
} Write, Run & Share Java code online using OneCompiler's Java online compiler for free. It's one of the robust, feature-rich online compilers for Java language, running the Java LTS version 17. Getting started with the OneCompiler's Java editor is easy and fast. The editor shows sample boilerplate code when you choose language as Java and start coding.
OneCompiler's Java online editor supports stdin and users can give inputs to the programs using the STDIN textbox under the I/O tab. Using Scanner class in Java program, you can read the inputs. Following is a sample program that shows reading STDIN ( A string in this case ).
import java.util.Scanner;
class Input {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Enter your name: ");
String inp = input.next();
System.out.println("Hello, " + inp);
}
}
OneCompiler supports Gradle for dependency management. Users can add dependencies in the build.gradle file and use them in their programs. When you add the dependencies for the first time, the first run might be a little slow as we download the dependencies, but the subsequent runs will be faster. Following sample Gradle configuration shows how to add dependencies
apply plugin:'application'
mainClassName = 'HelloWorld'
run { standardInput = System.in }
sourceSets { main { java { srcDir './' } } }
repositories {
jcenter()
}
dependencies {
// add dependencies here as below
implementation group: 'org.apache.commons', name: 'commons-lang3', version: '3.9'
}
Java is a very popular general-purpose programming language, it is class-based and object-oriented. Java was developed by James Gosling at Sun Microsystems ( later acquired by Oracle) the initial release of Java was in 1995. Java 17 is the latest long-term supported version (LTS). As of today, Java is the world's number one server programming language with a 12 million developer community, 5 million students studying worldwide and it's #1 choice for the cloud development.
short x = 999; // -32768 to 32767
int x = 99999; // -2147483648 to 2147483647
long x = 99999999999L; // -9223372036854775808 to 9223372036854775807
float x = 1.2;
double x = 99.99d;
byte x = 99; // -128 to 127
char x = 'A';
boolean x = true;
When ever you want to perform a set of operations based on a condition If-Else is used.
if(conditional-expression) {
// code
} else {
// code
}
Example:
int i = 10;
if(i % 2 == 0) {
System.out.println("i is even number");
} else {
System.out.println("i is odd number");
}
Switch is an alternative to If-Else-If ladder and to select one among many blocks of code.
switch(<conditional-expression>) {
case value1:
// code
break; // optional
case value2:
// code
break; // optional
...
default:
//code to be executed when all the above cases are not matched;
}
For loop is used to iterate a set of statements based on a condition. Usually for loop is preferred when number of iterations is known in advance.
for(Initialization; Condition; Increment/decrement){
//code
}
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
while(<condition>){
// code
}
Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
do {
// code
} while (<condition>);
Class is the blueprint of an object, which is also referred as user-defined data type with variables and functions. Object is a basic unit in OOP, and is an instance of the class.
class keyword is required to create a class.
class Mobile {
public: // access specifier which specifies that accessibility of class members
string name; // string variable (attribute)
int price; // int variable (attribute)
};
Mobile m1 = new Mobile();
public class Greeting {
static void hello() {
System.out.println("Hello.. Happy learning!");
}
public static void main(String[] args) {
hello();
}
}
Collection is a group of objects which can be represented as a single unit. Collections are introduced to bring a unified common interface to all the objects.
Collection Framework was introduced since JDK 1.2 which is used to represent and manage Collections and it contains:
This framework also defines map interfaces and several classes in addition to Collections.
| Collection | Description |
|---|---|
| Set | Set is a collection of elements which can not contain duplicate values. Set is implemented in HashSets, LinkedHashSets, TreeSet etc |
| List | List is a ordered collection of elements which can have duplicates. Lists are classified into ArrayList, LinkedList, Vectors |
| Queue | FIFO approach, while instantiating Queue interface you can either choose LinkedList or PriorityQueue. |
| Deque | Deque(Double Ended Queue) is used to add or remove elements from both the ends of the Queue(both head and tail) |
| Map | Map contains key-values pairs which don't have any duplicates. Map is implemented in HashMap, TreeMap etc. |