Tag Archives: problem

Producer and Consumer Problem


Self explanatory Producer and Consumer problem

Producer.java

package com.producer;

import java.util.ArrayList;

import java.util.Random;

public class Producer implements Runnable{

//Engine Batch ID reference

ArrayList engineList;

//Engine No is stored here

String str;

//Assigning the BATCH ID reference

public Producer(ArrayList engineList) {

this.engineList = engineList;

}

/*

* Produce Engines

*/

public void produce(){

//Random number for engine number

str = ""+Math.abs(new Random(System.currentTimeMillis()).nextLong());

//Only one thread can enter the BATCH for any operation

synchronized (engineList) {

//Add the Engine to the batch

engineList.add(str);

//Notify all other threads that the new engine is added to the BATCH

engineList.notifyAll();

}

//Print Engine Number

System.out.println("Produced :: ENGINE CHASIS NO ["+ str + "]");

}

@Override

public void run() {

System.out.println("Production started");

//10 Engine is to be produced

for(int i=0;i<10;i++){

try {

//Produce the engine

this.produce();

//Sleep for 2 seconds for the next operation

Thread.sleep(2000);

} catch (InterruptedException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

}

Consumer.java


package com.producer;

import java.util.ArrayList;

public class Consumer extends Thread{

//Engine Batch ID reference

ArrayList<String> engineList;

//Engine No is stored here

String str;

//Assigning the BATCH ID reference

public Consumer(ArrayList<String> engineList) {

this.engineList = engineList;

}

/*

* Consume Engines from the BATCH

*/

public  void consume(int index) throws InterruptedException{

//Only one thread can enter the BATCH for any operation

synchronized (engineList) {

//if the Batch has no engines

while(engineList.size() == 0){

//then wait for some time until you get a new engine to consume

engineList.wait();

}

//If the engine is deployed to the BATCH

if(engineList.size() >= 0){

//The consume the engine from the respective position

str = engineList.get(index);

}

}

//Print Engine Number that it has been consumed

System.out.println("Consumed :: -------> ENGINE CHASIS NO ["+ str + "]" );

}

@Override

public void run() {

//10 Engine has to be consumed

for(int i=0;i<10;i++){

try {

//Produce the engine

this.consume(i);

//Sleep for 3 seconds for the next operation

Thread.sleep(3000);

} catch (InterruptedException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

}

Main.java


package com.producer;

import java.util.ArrayList;

public class Main {

public static void main(String[] args) throws InterruptedException {

//ArrayList to store the produced engines - BATCH

ArrayList<String> engine = new ArrayList<String>();

//Producer taking the engine BATCH ID Reference

Producer producer = new Producer(engine);

//Consumer taking the reference of the engine BATCH ID Reference

Consumer consumer = new Consumer(engine);

//Threads

Thread prodThread = new Thread(producer);

Thread conThread = new Thread(consumer);

//Starting the production

prodThread.start();

//Start Consumption

conThread.start();

}

}


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Thoughts on Java that works


Disclaimer: This is just to get an idea of the implementation, please do not copy the source code

The problem reads like

SALES TAXES
Basic sales tax is applicable at a rate of 10% on all goods, except books,
food, and medical products that are exempt. Import duty is an additional
sales tax applicable on all imported goods at a rate of 5%, with no
exemptions.
When I purchase items I receive a receipt which lists the name of all the
items and their price (including tax), finishing with the total cost of the
items, and the total amounts of sales taxes paid.  The rounding rules for
sales tax are that for a tax rate of n%, a shelf price of p contains
(np/100 rounded up to the nearest 0.05) amount of sales tax.
Write an application that prints out the receipt details for these shopping
baskets…

Find the complete solved solution here

MARS ROVERS
A squad of robotic rovers are to be landed by NASA on a plateau on Mars.
This plateau, which is curiously rectangular, must be navigated by the
rovers so that their on-board cameras can get a complete view of the
surrounding terrain to send back to Earth.

A rover’s position and location is represented by a combination of x and y
co-ordinates and a letter representing one of the four cardinal compass
points. The plateau is divided up into a grid to simplify navigation. An
example position might be 0, 0, N, which means the rover is in the bottom
left corner and facing North.

In order to control a rover, NASA sends a simple string of letters. The
possible letters are ‘L’, ‘R’ and ‘M’. ‘L’ and ‘R’ makes the rover spin 90
degrees left or right respectively, without moving from its current spot.
‘M’ means move forward one grid point, and maintain the same heading.

Assume that the square directly North from (x, y) is (x, y+1).

Find the complete solved solution here