CareerCup

Write a program to print Fibonacci sequence in reverse order?

Design the Goodreads recommendation model.

Goodreads is a "social networking book" website that allows individuals to freely search its database of books.

- Any given user has a List of friends.
- User can add books to his/her shelve
- When a user logs in, we need to show the top 10 books owned by his friends

Example:
User1 has u2, u3, u4, u5 as friends

u2 owns b1, b2, …b10
u3 own b1, b2, b11…b20
u4 owns b1, b2, b11…b20
u5 owns b1, b33, b35, etc

topmost book is b1, second topmost book is b2 and so on.

If you maintain a cache of top 10 books in the user object for each of the users. How often will you update the cache ?

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.

Airbnb: Design webbrowser back button

Your web browser supports will support three actions: back, forward and open. The init webpage is “about:blank”.
Given a sequence of commands. Return the result page.

You have been given a generator string ab from which any number of strings can be generated recursively by inserting ‘ab’ at any location. You have been given an input string to check if that given string is valid or not.(i.e. generated by given with given string.)

eg.
Input: aabbab
Output: valid
Input: abbaab
Output: Invalid

I could not come up with a algorithm less than O(N*N)

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

Given a singly linked list, write code to find the most frequent element value in the list and its occurrence.

In case of duplicate number of occurrences, return the element value closest to the head.

A solution of time complexity O(N) average is preferred.



Sample Input: 1 2 3 4 2 3 2

Sample Output: Element 2 occurs 3 time(s)



Sample Input: 4 3 5 3 4 5

Sample Output: Element 4 occurs 2 time(s)

The wildcard regex can include the characters * and + .

‘+’ – matches any single character or empty character!

‘*’ – Matches any sequence of characters (including the empty sequence) For example,

Text = "baaabab":

regex = "ba*a++", output : true

regex = "ba*a+", output : true

regex = "a*ab", output : false

//empty string

Text=""

Regex= "+" , output : true

Given a multiple tree, and multiple nodes that need to be deleted,
It is required to return a list of nodes so that the children of these nodes can be found after the nodes have been deleted.

Gives you an int m, and a set of char (0,1,2,3,4,5,6,7,8,9)
Lets you implement a function that generates a id based on the characters in the set. Each time you return a string, it must be unique. satisfying the same character can not appear consecutively more than m times, such as m = 3, "1000" is valid,
"0000" is not valid.
The smaller the string, the better.

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 ?

A group of friends are tracking the miles per gallon for each of their cars. Each time one of them fills up their gas tank, they record the following in a file: His or her name The type of car they drove How many miles driven since they last filled up How many gallons purchased at this fill up Date of the fill Their data is formatted as a comma separate value (csv) file with the following format for each row:(#person,carName,milesDriven,gallonsFilled,fillupDate) Miles are recorded as floating-point numbers and gallons as integers. Please create a program that allows members of this group to determine the miles per gallon (MPG) of each of their cars during a specific time range. Note: person may have more than one so a time range query might need to output data for one or more cars. A skeleton class will be provided; your job will be to complete the program. The principal function for querying MPG is of the form (the exact name, data types, etc., can be learned by inspecting the "solution" class in the skeleton code): GetRangeMPG(PersonName, StartDate, EndDate) Returns list of objects containing (CarName, MPG) MPG is calculated as (total miles traveled during time period)/ (total gallons filled during time period. The dates you receive in the query should be treated inclusively.

To push dominoes, find out how many dominoes are standing in the end

For example, the input is ".R...RL..R..L..", which means pushing the 2nd, 6th, and 12th dominoes to the right and pushing the 8th and 15th dominoes to the left. This example returns 4th. 1,7,16,17 blocks are standing

The question is that there are a lot of vm, what is the total vm consumption max. For example, (2,4,8), (3,5,3) this input,
This means that 2 to 4 seconds have a memory usage of 8 and 3 to 5 seconds of 3, so the answer is 11 at 3 seconds.
Return 11 to it. Note that (1,2,3) and (2,3,4) such that the middle 3+4=7 is good.
Follow up is usage is not constant, such as (1,2,1,2) the first second usage is 1,
The second second is 2, the linear increase, the highest is how much.

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.

Search for a sorted integer in an integer array that has been rotated multiple times.

Print the bottom view of a Binary Tree.
ex-

1        

        2       3

    4       5       7

        8       9       10

result is 4, 8, 5, 9, 7, 10

Given an alphabet where we do not know the order of the letters also do not know the number of letters.

We are give an input list of tuples where each entry in the list gives an ordering between the 2 letters

Determine the alphabet order.

Ex-
<A, B>
<C, D>
<C, E>
<D, E>
<A, C>
<B, C>
Order is A, B, C, D, E

I was asked this question in a recent interview for a startup.

We have coffee vending machine with 3 buttons which can dispense 4oz, 7oz and 13oz of coffee.

Given a cup and the min and max amount(oz) of coffee it should fill. determine if the coffee vending machine can satisfy the condition.

The buttons can be pressed as many times as possible to fill the cup. Coffee shouldn't overflow..

AWS phone interview
Find the left view of binary tree
1
/ \
2 3
/\ \
4 5 6
/ /
7 8
/
9
return [1, 2, 4, 7, 9]

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

Given as list of movies in a csv file, extract the movie name and genre and be able to return a query based on the years and the genre.

Basically, Parsing a CSV input file and build an indexed data storage to allow search the data in time manner.

Given a list of tasks each with memory requirements and time, only one machine has K memory.
Do not consider the context switch, page swap, virtual memory, (for example, the machine has only 20mb memory, a task that requires 25MB of the task can only wait until there is enough memory to run it.) The running task cannot be suspended.
Ask how long it takes to complete all these tasks. . .

First common Ancestor of Binary tree . Java Solution needed.

Class Node {

Node Parent;
Node LeftChild;
Node rightChild;
int val;
}

publlic Node firstAncestor(Node leftNode, Node rightNode){
// We don't get the root node here. From left and right child we need to find it's parent and find the lowest common ancestor.
}

If b == “1”:
quit()

1) You sell roses. Each rose cost 30 cents to buy and you can sell them for $10 a dozen.
a) How many you need to sale to break even if you bought 600 roses?
b) Tomorrow is holiday - there's 20% likelihood you will sale 600 roses, 50% likelihood of selling 900 roses and 30% likelihood of selling 1200 roses. How many would you buy to maximize profit?

Write a method that can take in an unordered list of airport pairs visited during a trip, and return the list in order:

Unordered: ("ITO", "KOA"), ("ANC", "SEA"), ("LGA", "CDG"), ("KOA", "LGA"), ("PDX", "ITO"), ("SEA", "PDX")
Ordered: ("ANC", "SEA"), ("SEA", "PDX"), ("PDX", "ITO"), ("ITO", "KOA"), ("KOA", "LGA"), ("LGA", "CDG")

Given a binary tree, where each node represents an integer, find the max value of path sum.

April Google Interview 1/4
A = a+b-c-a-b-c-a-b (Tree)
B = b+a+c+a+b-c+b (Tree)
is A equal to B