CareerCup

You have a big .csv file (say the size is 3GB). How efficiently you can process it and put the records in database?

A program stores total order numbers arrived at different time. For example, at 1.15 pm the program got 15 order, at 1.30 pm, the program got 20 order and so on.Now we need to design the data structure so that we can query the total orders we got in a time range efficiently. For this example, we can query as How many orders we have got between 1 and 2 pm? Ans will be 15+ 20 = 35

Given a file (which can be considered as a String with comma delimiter for the complexity of the question) of usernames and a value k, find top k usernames (with number of logins) who logged into the system the most.

For example -
Input:
User (String) = user1, user4, user2, user1, user3, user1, user2, user3
k (int) = 2

Output:
user1 (3)
user2 (2)
user3 (2)

- Both user2 and user3 should be included since both has same number of logins

Write a java method to find the output with best time and space complexity.

Given a list of numbers ex:(2,15,8) as a string with out any delimiters like space or ',' as str = "2158"; is there a way to parse the string an identify which one is double digit or single digit number ?? like 2,8 are single digit number and 15 is a double digit number

Build an in-memory DB that supports many commands and transactions.
Similar to redis database (Redis.io)

OO design for implementing table tennis game between two players? I just want the class diagram not the whole implementation. Only the class/interfaces names will help.

The input is being read in from a file called input.txt, in this format: 22|Data Structures|45
23|English|52
22|English|51
26|Data Structures|72
23|Data Structures|61
21|English|81

Each line consists of three fields "Student ID," "Subject," and "Marks." "Student ID" and "Marks" are integers and "Subject" is a string that does not contain '|' or newlines. There can be any number of students and up to 6 subjects. The fields are separated by the '|' character.

Currently, the existing program reads the input and creates an ArrayList<String> from the lines of input. Then it calls a method processData on this ArrayList, and prints the returned data to the output file. Unfortunately, processData currently does not do anything useful - it just returns an empty `Map.

You have to modify processData to compute the marks scored in each subject by the student with the lowest ID (who has actually appeared for that test). Thus, processData will returns a Map that maps each Subject to the marks scored. In other words, the map will contain each subject name as a key, and the marks scored by the student with the lowest ID as the value for that entry.

If your program is run with the input given above, it should produce the following output:

Data Structures: 45
English: 81

Please read this expected output carefully to understand exactly what you're expected to compute.

Plz help me solve urgent.

Implementation of Hashmap with overriding equals() and HashCode() method to display unique values in the class object.

Jack love playing games, Gluttonous snake( an old game in Nokia era) is one of his favorite. However, after playing gluttonous snake so many times, he finally got bored with the game, so he changed the rules:

Rule 1: Write a code to find the Max sum path in a grid (2-D array), with dimension with n rows and m column (1<=n,m<=500)

Rule 2: In the 2D Array, each cell (elements) contains a value v in the array is from (-1<=v<=99999)

Rule 3. You can start from any position of the leftest column (border) of the array to the rightest(border) column of the array to calculate the Max Sum path.

Rule 4. You can move up, right, down, and CAN'T move left, and can visit each element only one time.

Rule 5.If the element is -1, it means the path is blocked, and you can't go through the path (calculate it in the sum), you have to choose other path to calculate the sum.

For example, if a 4*4 array grid
{{-1,3,2,1}
{2,-1,2,4}
{2,2,-1,3}
{4,2,1,2}};
The max sum path is : (from grid[4][0])
4-->up-->2-->left-->2-->down-->2-->left-->
1-->left-->2-->up-->3-->up-->4-->up-->1

and the sum is 4+2+2+2+1+2+3+4+1 =21

Thank you

Here is my code, I am new in Java and there is still lots of improvements
import java.util.*;
public class MainClass {

public static void main(String[] args) {

@SuppressWarnings("resource")
Scanner rowDimension = new Scanner(System.in);
System.out.print("Enter the number of rows: ");
int firstInput = rowDimension.nextInt();

@SuppressWarnings("resource")
Scanner columnDimension = new Scanner(System.in);
System.out.print("Enter the number of columns: ");
int secondInput = columnDimension.nextInt();

//Input two number to generate 2D Array
Integer [][] array = new Integer[firstInput][secondInput];
//The purpose of the array is check the wall (cell value = -1)
boolean [][] visited = new boolean[firstInput][secondInput];

//Use Math.random() to generate the cell of the array
int[][] randomTable = new int[firstInput][secondInput];
for (int row = 0; row < firstInput; row++) {
for (int column = 0; column < secondInput; column++) {
// multiply by 1000000 to get a number between 0 and 99999
randomTable[row][column] = (int)(Math.random() * 1000000 -1);
System.out.print(randomTable[row][column] + " ");
}
System.out.println();
}

//Start form the left-down location of grid
int i = firstInput-1, j = 0;
visited[i][j] = true;
double sum = array[i][j];
while(true)
{
int max = -1;
int maxi = 0, maxj = 0;

//Case1 : choose path: UP
if(i-1 >= 0 && i-1<= firstInput-1 && j>=0 && j<= secondInput-1 && array[i-1][j] != null && array[i-1][j]>max && !visited[i-1][j])
{
max = array[i-1][j];
maxi = i-1;
maxj = j;
}

//Case2 : choose path: Down
if(i+1 >= 0 && i+1<= firstInput-1 && j>=0 && j<= secondInput-1 &&array[i+1][j] != null && array[i+1][j]>max && !visited[i+1][j])
{
max = array[i+1][j];
maxi = i+1;
maxj = j;
}

//Case3 : choose path: Right
if(i >= 0 && i<= firstInput-1 && j+1>=0 && j+1<= secondInput-1 && array[i][j+1] != null && array[i][j+1]>max && !visited[i][j+1])
{
max = array[i][j+1];
maxi = i;
maxj = j+1;
}

i = maxi;
j = maxj;
visited[i][j] = true;
sum += max;

//To the destination : Right-Up location of the grid
if(i == 0 && j == secondInput-1)
break;
}
System.out.println(sum);

}
}

Today is school picture day and everybody,
including the teacher, has lined up in a single line for the class picture.
Design an O(n log n) Java code that computes the minimum number of swaps necessary to be in order

Given is a large paper with n different points with coordinates (x1, y1),(x2, y2), . . . ,(xn, yn).
Keep folding at 45 degres

find consecutive integers in a list that give you the biggest sum

Like for -2 5 -1 7 -3 it would be 5 -1 7

Without using arrays, write a Console application that reads in a list of integers, one per line, until a sentinel value of 0 (which you should be able to change easily to some other value). When the sentinel is read, your program should display the following numbers:
Smallest and largest values in the list,
Second smallest and second largest values in the list

This is what I have so far.

public static void main (String[] args)
    {int min = Integer.MAX_VALUE;
    int max = Integer.MIN_VALUE;
    int SecondMax = Integer.MAX_VALUE;
    int SecondMin = Integer.MAX_VALUE;

    Scanner s = new Scanner(System.in);
    while (true) {
      System.out.print("Enter a Value: ");
      int val = s.nextInt();

      if (val == 0) {
          break;
                    }
      if (val < min) {
          min = val;
                     }
          
      if (val > max) {
         max = val;
                     }
                 }

    System.out.println("The smallest number is: " + min);
    System.out.println("The largest number is: " + max);
    System.out.println("The second smallest number is: " + SecondMin);
    System.out.println("The second largest number is: " + SecondMax);
    }

}}

Implement following interface so that multi-put is atomic. Expect multiple producers and consumers inserting to and extracting from this queue implementation.

/**
* threadSafe bounded blocking queue implementation. Expected to be used in a
* Producer->Consumer pattern
*/
public interface MultiPutBlockingBoundedQueue<E> {

/**
* Sets the capacity of the buffer. Can be called only once. If called more
* than once or if the passed capacity is <= 0, throw an exception.
*/
public void init(int capacity) throws Exception;

/**
* Get the next item from the queue throws Exception if not initialized
*/
public E get() throws Exception;

/**
* Put the item to the tail of the queue. throws Exception if not
* initialized
*/
public void put(E obj) throws Exception;

/**
* Put the list of items in an atomic manner. The list can be more than the
* capacity throws Exception if not initialized
*/
public void multiput(List<E> objs) throws Exception;

}

Find a 1st non-repeated char in the string for e.g. if string is "Salesforce is the best company to work for” returns 'l'

given a string, calculate the frequency of characters, output the array with the letter and frequency. (such as: for “abbcdc”, the output should be (a,1),(b,2),(c,2),(d,1))

I have a photo storage service. The actual photos are present in some storage and the index of these photos is present at some other place. The index is huge, say trillions of photos. Design the class for index node of each photo (with attributes like name*, date*, size*, accesscontrol, camera details, shot details, etc) such that 1. It is serializable. 2. For faster processing, I am interested in first 3 attributes. When deserializing the bytes of object, parse these 3 attributes i.e. instead of deserializing whole class, deserialize only part of the class (members marked by*), other members of class should be deserialized on demand with another call.
How will you test the performance of your serialization/ deserialization?

How do you create your own garbage collector? How do you find whether objects in memory are orphans in order to purge them?

Write a method that takes in a positive integer, return the number of 2s between 0 and the input number.

If the input value given is 13, it should return 2 as the number 2 and 12 are between 0 and 13.

If the input value given is 21, it should return 3 as the number 2,12 and 20 are between 0 and 21.

Is java pass by value or pass by reference?
Then he asked various question related to this.
What if i pass integer, array list or object will the change reflect in the original function.
In case of object will we have different behavior when i set it to null in the called function or when I call its method(setName("") for example ).

Asked me to write an API. Then ask:

Consider how the API could support 3rd party applications which need to perform some logic based on the structure and content of a filter in a type-safe manner.

It is part of a programming exercise.

Input is a combination of arbitrary complex filters. For example:

name = "smith" AND age > 9 OR Not(city = "New York")

It asks for a string representation, including the ability to generate and parse filters from the string representation. (you are not required to implement the string parsing logic since this could take too long)

Hint: give an example of a tree data structure.

Test Question

Problem Two: Conference Track Management

You are planning a big programming conference and have received many proposals which have passed the initial screen process but you're having trouble fitting them into the time constraints of the day -- there are so many possibilities! So you write a program to do it for you.

• The conference has multiple tracks each of which has a morning and afternoon session.
• Each session contains multiple talks.
• Morning sessions begin at 9am and must finish by 12 noon, for lunch.
• Afternoon sessions begin at 1pm and must finish in time for the networking event.
• The networking event can start no earlier than 4:00 and no later than 5:00.
• No talk title has numbers in it.
• All talk lengths are either in minutes (not hours) or lightning (5 minutes).
• Presenters will be very punctual; there needs to be no gap between sessions.

Note that depending on how you choose to complete this problem, your solution may give a different ordering or combination of talks into tracks. This is acceptable; you don’t need to exactly duplicate the sample output given here.

Test input:
Writing Fast Tests Against Enterprise Rails 60min
Overdoing it in Python 45min
Lua for the Masses 30min
Ruby Errors from Mismatched Gem Versions 45min
Common Ruby Errors 45min
Rails for Python Developers lightning
Communicating Over Distance 60min
Accounting-Driven Development 45min
Woah 30min
Sit Down and Write 30min
Pair Programming vs Noise 45min
Rails Magic 60min
Ruby on Rails: Why We Should Move On 60min
Clojure Ate Scala (on my project) 45min
Programming in the Boondocks of Seattle 30min
Ruby vs. Clojure for Back-End Development 30min
Ruby on Rails Legacy App Maintenance 60min
A World Without HackerNews 30min
User Interface CSS in Rails Apps 30min

Test output:
Track 1:
09:00AM Writing Fast Tests Against Enterprise Rails 60min
10:00AM Overdoing it in Python 45min
10:45AM Lua for the Masses 30min
11:15AM Ruby Errors from Mismatched Gem Versions 45min
12:00PM Lunch
01:00PM Ruby on Rails: Why We Should Move On 60min
02:00PM Common Ruby Errors 45min
02:45PM Pair Programming vs Noise 45min
03:30PM Programming in the Boondocks of Seattle 30min
04:00PM Ruby vs. Clojure for Back-End Development 30min
04:30PM User Interface CSS in Rails Apps 30min
05:00PM Networking Event

Track 2:
09:00AM Communicating Over Distance 60min
10:00AM Rails Magic 60min
11:00AM Woah 30min
11:30AM Sit Down and Write 30min
12:00PM Lunch
01:00PM Accounting-Driven Development 45min
01:45PM Clojure Ate Scala (on my project) 45min
02:30PM A World Without HackerNews 30min
03:00PM Ruby on Rails Legacy App Maintenance 60min
04:00PM Rails for Python Developers lightning
05:00PM Networking Event

Test Question, this is a test question

Given an array of strings with only lowercase letters , create a function that returns an array of those same strings, but each string has its letters rearranged such that it becomes a palindrome (if possible, if not, return -1)

Given a 2-dimensional square matrix, rotate the matrix clockwise. Imagine concentric circles. Input from stdin: first line is length, subsequent lines are rows of the matrix. Output the matrix to stdout. This was one of the questions. You have 2 hrs to complete it.

Given a positive integer, rearrange its digits to find the greatest positive integer. Expected time/space complexity O(1). I was to do this in space O(1), time O(n).

Company will start a new marketing campaign targeting the users according
to their purchasing profiles.

This campaign has 3 kinds of messages each one targeting one group of customers:

Message 1 - targets the 25% of customers that spend most at the site

Message 2 - targets the 25% of customers that spend least at the site

Message 3 - targets the rest of the customers.

Given the list of purchases made during the week, write a program that lists
what kind of message each customer will receive.

Each purchase in this list features the customer id, the purchase amount among other information.

Design a system java same as relational database.
For example,
You Have employee table as bellow:

ID | Name | Manager | Salary

Now you can execute queries like :

select * from Employee where ID= ' something'
    select * from Employee where Name= ' something'
    select * from Employee where salary = ' something'

In same way you have a class Emplyee as bellow:

class Employee
   {
     String ID;
     String Name;
     String Salary;
     String Manager;
   }

Now I want to query on this class as same as the sql queries above,
How can I do it efficiently?

The code should be optimized on time complexity and space complexity.