Computer scienceProgramming languagesJavaWorking with dataMultithreadingBasics of threads

Thread management

Calculate the number of distinct characters

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Below is the code that reads a string from the standard input and calculates the number of distinct characters in the string. For some reason, the developer Rebecca decided to perform calculations in a new thread. Sadly, her solution doesn't work correctly. Try to fix it.

Additional explanations: the implemented class SlowStringProcessor extends Thread and overrides the method run. It calculates the number of distinct characters passed to the constructor. The class has a getter getNumberOfUniqueCharacters() that returns the calculated number or 0 if the thread has not calculated the number yet. Keep in mind that SlowStringProcessor works quite slow.

Note: you don't need to write SlowStringProcessor. It will be added to your solution automatically.

Sample Input 1:

multithreading

Sample Output 1:

Write a program in Java 17

import java.util.Scanner;

import java.util.Arrays;

public class Main {

private static long mainThreadId = Thread.currentThread().getId();

// Fix this method

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

Scanner scanner = new Scanner(System.in);

String str = scanner.nextLine();

SlowStringProcessor processor = new SlowStringProcessor(str);

System.out.println(processor.getNumberOfUniqueCharacters());

}

//Don't change the code below

static class SlowStringProcessor extends Thread {

private final String s;

private volatile long numberOfUniqueCharacters = 0;

public SlowStringProcessor(String s) {

this.s = s;

}

@Override

public void run() {

final long currentId = Thread.currentThread().getId();

if (currentId == mainThreadId) {

throw new RuntimeException("You must start a new thread!");

}

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