CareerCup

As you know, most Operating Systems are written in Java, what’s special about pointers in Java ? *

Use synchronized, wait() and notify() to write a program such that below mentioned conditions are fulfilled while reading and writing data to a shared resource.

When a write is happening, no read or other write should be allowed(read and write threads should wait)

When a read is happening, no write should be allowed (write threads should wait) but. other read threads should be able to read.

Donot use any API classes e.g. ReadWriteLock, AtomicInteger etc..

Shopping Cart Programming test.
There are multiple types of customer(Regular, Premium) they have been given a discount based on their purchase amount. for e.x
Premium Customer
1) 0-$5000 0%
2) $5000-$10000 10%
3) 10000 - above 20%

Regular Customer
1) 0-$4000 10%
2) $4000 - $8000 15%
3) $8000 - $12000 20%
4) $12000 - above 25%

Read input from console:
Input:
Regular
$5000
Output:
$5000
Input:
Premium
$7000
Output
$8000

You have three Arrays.
A = {2, 5, 3, 2, 8,1}
B = {7, 9, 5, 2, 4, 10, 10}
C = {6, 7, 5, 5, 3, 7}

make an array from this three arrays which elements is present in at least two array.

This question was followed by instead of three arrays. If you have a list of array then what will be the solution? Also what will be the time complexity?

A happy number is defined by the following process. Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy numbers, while those that do not end in 1 are unhappy numbers.
Input:
Your program should read lines of text from standard input. Each line contains a single positive integer, N.
Output:
If the number is a happy number, print 1 to standard output. Otherwise, print 0.

You have oracle database table , and AURORA AWS table with same fields , write a java lambda function to migrate data from oracle table to aurora. Also it should be realtime, if a new record is added to oracle it should update aurora db table as well.

Maximum Pairs

You are given N pencils. You have to make pairs of pencils.

The condition for making pairs is:
If(a,b) is any pair of pencils then b >= 2 * a. Here a and b are the sizes of pencils.

Now you have to find out the number of such pairs and the number of pencils which could not be paired with any pencils.

Note:

You need to pair the pencils in such a manner that the maximum number of pairs are formed.

Input Format:

The first line consists of number of test case T.
Each test case consist of:
- First line consists of a single integer N.
- Second line consists of N space-separated integers denoting the size of pencils Si.

Output Format:

For each test case, print two space-separated integers, first denoting the number of pairs formed and second denoting the number of unpaired pencils.
Answer for each test case should come in a new line.

Constraints
1<T<=10
1<=N<=10^5
0<=Si<=10^5

Sample Input

2
5
1 2 3 4 5
4
1 2 4 4

Sample Output

2 1
2 0

Explanation

In the first test case:-
we can form the following pairs:
(1, 3), (2, 4) and 5 remains unpaired hence maximum pairs are 2
In second test case:-
(1, 4), (2, 4) are two pairs hence no pencil left unpaired

public class Test {
    public static void main(String[] args) {
          }

    static int[] solve(int[] arr) {
        // the value at first index of array to be returned is number of pairs
        // formed and value at second index is unpaired swords.
           }
}

Int minSemsToFinishAllCourses(Map<string, list<string>)

Given a map containing courses and the list of prerequisites for that course in no particular order, determine the least number of semesters to finish all the courses.
You have to take all prerequisites before you take a given course.

Eg.
Calculus : English, math2
Math2: math 1, Arabic, english
Math1: english
English: <>
Arabic:<>

Give an algorithm for the above and code using java

Given the arraylist<meals> input, find the number of dishes with unique ingredients.

class meals{
        String cuisine;
        ArrayList<String> dish = new ArrayList<String>();
        meals(String s, String[] arr){
                cuisine = s;
                for(String i:arr){
                    dish.add(i);
                }
        }
    }

Example:
Input: [
{
"cuisine" : "American",
"dish" : ["lettuce", "cheese", "olives", "tomato"]
},
{
"cuisine" : "Mexican",
"dish" : ["lettuce", "cheese", "pepper", "tomato"]
},
{
"cuisine" : "French",
"dish" : ["lettuce", "cheese", "pepper", "tomato"]
},
{
"cuisine" : "Continental",
"dish" : ["lettuce", "cheese", "olives", "tomato"]
},
]

Output: 2

Because there are two unique ingredient-dishes; {Mexican, French} and {American, Continental}.

I have tried different methods, but could not get to the solution. Thank you!

print hockey stick number in pascal triangle where row of triangle can be upto 30000 and length of stick can be upto 100.

Two players and are playing a game.They are given binary numbers as input. Each binary number is represented as a string of characters '0' or '1'. The string always ends at '1'. In one move each player decides a bit position . Then he visits all the numbers and if their bit at that position is '1' then he changes it to '0'. It is mandatory to flip(change '1' to '0') bit of atleast one number in each move. The player who is unable to make a move loses. Player begins the game.

Input
First line contains a number as input. Next lines contain a binary string each.

Output
Print A if player A wins , B otherwise. In the next line print the move number of the last move of the winning player.

I want to implement a simple HTTP Denial-of-Service protection. There are clients that can send HTTP request to a Server (i.e. a GET Method of http://10.1.1.2:8080/?clientId=7)

if in an interval of 10 seconds more then 10 request comes from a specific client the 11th, 12th.. requests will get blocked. until 10 seconds from the first request will pass and then a new time windows of 10 seconds will be open. the idea is no more than 10 requests per 10 secs.

The time frame starts on each client’s first request and ends 10 seconds later.

I want to implement this logic on the server. Which data structures/collection/custom made object would you build to implement such a logic...

it is also important to have a threats safe solution.. and performances is also a factor here..

Thanks.

Round 3- Find the first duplicate occurence of a number in an array

Round 3 - Write a java program to print a matrix in spiral

Round 2 - Write a java program to determine if a 10 digit number is magic number.A number is magic number if it has all digits between 1 to 6 occuring in it or if it has any number between 0 to 9 occuring thrice or if it contains three consecutilvely increasing or decreasing digits differing by 1 example 345 or 543

Round 2 - write java code to create the following pattern
*
* * *
* * * * *
* * * * * * *
* * * * * * * * *

Round 1-question 1 - given an array of stock prices for n days.Write an algorithm to maximize the profit of a customer such that he can buy and sell only once.
-Question 2
Prove that complexity for searching in arraylist is o(n)
and adding is o(1)

write java code to create the following pattern
*
* * *
* * * * *
* * * * * * *
* * * * * * * * *

Round 1-Question 1
1)Given an array of stock prices for 7 continuous days.Write an algorithm to maximize the profit for a customer who buys stock on any day and sells it later.Buying and selling can happen only once and selling should happen on any day after buying

I was asked to design a system on a whiteboard which simulate a executor.
This system has a method that is being triggered every second. I need to add logic to the method (i.e. run jobs).
There is also a method called job_arrived() that is called when a new job arrives.. I need to implement it as well.
I needed to implement a system which tries to run each job right when it is arrived (it has a return value that gets a success status from a black box service). if the job ran successfully that's the end of it..
if not I need to re-run it after 2 seconds (and if that fails as well - there will be no re-runs).
of course - more than one job can be accepted each second.
I was asked to describes the system (describe the classes and method) and consider the system to be large scale one (meaning.. threading is in order here..).
The answer I gave was apparently not multi threaded enough..
any idea to what I should have done?
Thanks guys

https://codejamanalysis.wordpress.com/2017/03/18/crossover-problem-super-stack/

Any Optimized Solution to avoid TLE for 4 test cases. I have tried by implementing Stack using Doubly Linked List.
Still not able to pass test cases!!!

There is a list of 20 words. 10 of them are good works, and 10 of them are bad words. Write a regex of not more than 25 characters which would tell if given word is good or bad. Input would only contain one of these 20 words.
Good words: papa, book, home, cars, jolly, sugar, friend, mother, father, bloomiest
Bad words: ache, slow, torn, slum, boom, rival, wrong, cholera, revenge, arrogant

Input: book
Output: Good

Input: boom
Output: bad

Write Java Code using regex pattern

1. There is a list of 20 words. 10 of them are good works, and 10 of them are bad words. Write a regex of not more than 25 characters which would tell if given word is good or bad. Input would only contain one of these 20 words.
Good words: papa, book, home, cars, jolly, sugar, friend, mother, father, bloomiest
Bad words: ache, slow, torn, slum, boom, rival, wrong, cholera, revenge, arrogant

Input: book
Output: Good

Input: boom
Output: bad

What is the issue with this Producer Consumer Problem. Can you fix it.

public class ProducerConsumerProb {

	public static void main(String[] args) {
		Container container = new Container();
		Turn turn = Turn.PRODUCER;
		Producer p = new Producer(container, turn);
		Consumer c = new Consumer(container, turn);
		Thread pro = new Thread(p);
		Thread con = new Thread(c);
		pro.start();
		con.start();
	}

	public static class Producer implements Runnable{
		Container container;
		Turn turn;
		public Producer(Container integer,Turn turn) {
			this.container = integer;
			this.turn = turn;
		}
		
		@Override
		public void run() {
			for(int i=0;i<10;i++){
				Turn temp = null;
				while(true){
					synchronized (turn) {
						temp = turn;
					}
					if(temp == Turn.PRODUCER){
						break;
					}
				}
				synchronized (turn) {					
					container.setI(i);
					turn = Turn.CONSUMER;
				}
			}
		}
	}
	
	public static class Consumer implements Runnable{
		Container container;
		Turn turn;
		public Consumer(Container integer,Turn turn) {
			this.container = integer;
			this.turn = turn;
		}
		
		@Override
		public void run() {
			for(int i=0;i<10;i++){
				Turn temp = null;
				while(true){
					synchronized (turn) {
						temp = turn;
					}
					if(temp == Turn.CONSUMER){
						break;
					}
				}
				synchronized (turn) {					
					System.out.println(container.getI());
					turn  = Turn.PRODUCER;
				}
			}
		}
		
	}
	
	public static class Container{
		Integer i = new Integer(0);
		

		public int getI() {
			return i;
		}

		public void setI(int i) {
			this.i = i;
		}
				
	}
	
	enum Turn{
		PRODUCER,CONSUMER;
	}
}

There are hierarchy of class like super class and sub class. Yo have to make sure only one object can be create for any class using new keyword. How you implement the class.

find the sum of bit wise OR of minimum and Maximum element of all the subsets whose length is greater than 2 of the given of set.

for ex:-

{1,2,3} is set
then possible subsets of length is{ 1,2},{1,3},{2,3}{1,2,3} answer 1|2 +1|3 +2|3 +1|3=12

Let’s say you have two input arrays with sorted elements. Find the union.

a[] = {2, 10, 14, 19, 51, 71}
b[] = {2, 9, 19, 40, 51}

Union = {2, 9, 10, 14, 19, 40, 51}

why we have a such long number value for object's hashcode in java.can we not have any small numbers or why java is giving that much large number for any object hash code ?

List<Integer> list=Arrays.asList(1,2,3,4,5,6);
Iterator it=list.iterator();
while(it.hasNext()){
System.out.println(it.next());
}
The above code will iterate sequentially through 1 to 6. Can we iterate the same list alternatively so that it will print 1,3,5 without changing the while loop.

Given a number, rearrange the digits of that number to make a higher number, among all such permutations that are greater,one of them is the smallest, Find the smallest greater permutation (the next Permutation).

Examples:
next_permutation (12) = 21
next_permutation (315) = 351
next_permutation (583) = 835
next_permutation (12389) = 12398
next_permutation (34722641) = 34724126