CareerCup

#include <iostream>
#include <thread>
#include <condition_variable>
#include <mutex>

using namespace std;

int count = 0;
mutex m;
condition_variable cv;

void Run(int start, int end) {
	while (true) {
		unique_lock<mutex> lock(m);
		if (::count >= end) {
			break;
		}
		while (::count < start) {
			cv.wait(lock);
		}
		++::count;
		cout << this_thread::get_id() << " incremented to " << ::count << endl;
		cv.notify_all();
	}
}

int main()
{
	thread t1(Run, 80, 100);
	thread t2(Run, 20, 80);
	thread t3(Run, 0, 20);
	t1.join();
	t2.join();
	t3.join();
}

Just want to solve using high level wait() and notify()

package com.careercup.main;

public class Counter {

	public static class Thread1 extends Thread {

		private final Object lock;

		Thread1(Object lock) {
			this.lock = lock;
		}

		@Override
		public void run() {
				for (int i = 0; i < 20; i++) {
					counter++;
				}
				System.out.println("Thread1 incremented counter to :"+counter);
				synchronized (lock) {
					lock.notifyAll();
				}
		}
	}

	public static class Thread2 extends Thread {
		private final Object lock;

		Thread2(Object lock) {
			this.lock = lock;
		}
		@Override
		public void run() {
			synchronized (this) {
				try {
					System.out.println("Thread2 waiting");
					this.wait();
					for (int i = 0; i < 60; i++) {
						counter++;	
					}
					System.out.println("Thread2 incremented counter to :"+counter);
					synchronized (lock) {
						lock.notifyAll();
					}
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
			
		}
	}

	public static class Thread3 extends Thread {
		@Override
		public void run() {
			synchronized(this){
				try {
					System.out.println("Thread3 waiting");
					this.wait();
					for (int i = 0; i < 20; i++) {
						counter++;
					}
					System.out.println("Thread3 incremented counter to :"+counter);
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
		}
	}
	

	public static int counter = 0;

	public static void main(String[] args) {
		Thread thread3 = new Thread3();
		Thread thread2 = new Thread2(thread3);
		Thread thread1 = new Thread1(thread2);
		thread1.start();
		thread2.start();
		thread3.start();
		try {
			thread1.join();
			thread2.join();
			thread3.join();
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}

}

package com.example.test;

public class ThreadTest {

	public static void main(String[] args) {
		
		ThreadCounter counter = new ThreadCounter();
		Thread t1 = new Thread(counter, "T1");
		Thread t2 = new Thread(counter, "T2");
		Thread t3 = new Thread(counter, "T3");
		
		t1.start();
		t2.start();
		t3.start();
	}
}

class ThreadCounter extends Thread{
public static int counter = 1;
	
	
	@Override
	synchronized public void run() {
		int n=20;
		if(Thread.currentThread().getName().equals("T2")){
			n = 60;
		}
		for(int i=0;i<n;i++){
			System.out.print("Running thread: "+Thread.currentThread().getName()+" ");
			System.out.println(counter);
			counter++;
		}
	}
}

package com.example.test;

public class ThreadTest {

public static void main(String[] args) {

ThreadCounter counter = new ThreadCounter();
Thread t1 = new Thread(counter, "T1");
Thread t2 = new Thread(counter, "T2");
Thread t3 = new Thread(counter, "T3");

t1.start();
t2.start();
t3.start();
}
}

class ThreadCounter extends Thread{
public static int counter = 1;


@Override
synchronized public void run() {
int n=20;
if(Thread.currentThread().getName().equals("T2")){
n = 60;
}
for(int i=0;i<n;i++){
System.out.print("Running thread: "+Thread.currentThread().getName()+" ");
System.out.println(counter);
counter++;
}
}
}

import java.util.List;

package com.example.demo;

public class ThreadTest {

	public static void main(String[] args) {

		ThreadCounter counter = new ThreadCounter();
		Thread t1 = new Thread(counter, "T1");
		Thread t2 = new Thread(counter, "T2");
		Thread t3 = new Thread(counter, "T3");

		t1.start();
		t2.start();
		t3.start();
	}
}

class ThreadCounter extends Thread {
	public static int counter = 1;
	public static String currentThread = "T1";
	int n = 20;

	@Override
	synchronized public void run() {
			while (counter < 100) {
				if (!Thread.currentThread().getName().equals(currentThread)) {
					try {
						wait();
					} catch (InterruptedException e) {
					}
				} else {
					for (int i = 0; i < n; i++) {
						System.out.print("Running thread: " + Thread.currentThread().getName() + " ");
						System.out.println(counter);
						counter++;
					}

					if (Thread.currentThread().getName().equals("T1")) {
						currentThread = "T2";
						n = 60;
					} else if (Thread.currentThread().getName().equals("T2")) {
						currentThread = "T3";
						n = 20;
					}

					notifyAll();
			}
		}
	}
}