SDE - 1

You are Harshad Mehta’s friend. He told you the price of a particular stock for the next ‘N’ days. You can either buy or sell a stock. Also, you can only complete at most 2-transactions. Find the maximum profit that you can earn from these transactions. You can take help from Mr. Mehta as well.

Critical section is the code segment of a process in which the process may be changing common variables, updating tables, writing a file and so on. Only one process is allowed to go into critical section at any given time (mutually exclusive).The critical section problem is to design a protocol that the processes can use to
co-operate. The three basic requirements of critical section are:
1. Mutual exclusion
2. Progress
3. bounded waiting
Bakery algorithm is one of the solutions to CS problem.

You are given an array/list ‘ARR’ consisting of ‘N’ distinct integers arranged in ascending order. You are also given an integer ‘TARGET’. Your task is to count all the distinct pairs in ‘ARR’ such that their sum is equal to ‘TARGET’.

There are two ways to create a thread in Java:
1) By extending Thread class :
The Thread class provides constructors and methods for creating and operating on threads. The thread extends the Object and implements the Runnable interface.
// start a newly created thread.
// Thread moves from new state to runnable state when it gets a chance, executes the target run() method
public void start() 
2) By implementing Runnable interface.
Any class with instances that are intended to be executed by a thread should implement the Runnable interface. The Runnable interface has only one method, which is called run().
// Thread action is performed
public void run()