CareerCup

write a program to validate a IPV4 address

Given an array of positive, unique, increasingly sorted numbers A, e.g. A = [1, 2, 3, 5, 6, 8, 9, 11, 12, 13]. Given a positive value K, e.g. K = 3. Output all pairs in A that differ exactly by K.
e.g. 2, 5
3, 6
5, 8
6, 9
8, 11
9, 12
what is the runtime for your code?

Design Live comments. If your facebook.com homepage is open with bunch of feeds and if someone comments on those feeds, the comments should automatically show up in facebook.com home page without refreshing the page. Feeds could be a simple status update by a friend, post in a group, post by a person you're following, post in a page you've liked etc.

Few things what they are looking for -
1. How do you solve it initially and how do you scale it?
2. How do you scale push model in-case if you choose PUSH model to solve it?
3. If push cannot scale how do you solve it?
4. How pull model solves it?
5. When will you use push vs pull?

Hadoop architecture:
How would you deisgn a Craiglist based architecture ?
What hadoop components you would use. Given the user can search for a car and the car listings get updated frequently. How would you design the craglist system. What database you would use and how would you process the data ?

3. Implement a function that returns the i-th most popular item sold at Amazon. You cannot rely on any libraries.

class Item {
String itemId;
int quantitySold;
}

/**
* Find the ith most popular item in the list.
*/
String find(List<Item> items, int i) {
// your code goes here
}

2. Suppose you are given a puzzle that is represented as a matrix with 0s and 1s, where a 0 indicates you’re allowed to move into that position and 1 means you’re not allowed to move in that position. Write a function that given a start position and an end position, returns a boolean value indicating if there exists a path from start to end. You are only allowed to move up, down, right or left. Diagonal movement is not allowed.

Example #1

Input
0 0 1 0 1
0 0 0 0 0
0 1 1 1 1
0 1 1 0 0

start: 4,1
end: 0,3

Output
true

Example #2

Input
0 0 1 1 1
0 1 0 0 0
1 1 1 1 1
0 0 0 0 1

start: 0,0
end: 1,2

Output
false

Example #3

Input
0 0 1 1 1
0 1 0 0 0
0 1 1 1 1

start: 0,0
end: 2,1

Output
False

class Position {
final int x, y;
public Position(final int x, final int y) {
this.x = x;
this.y = y;
}
}

boolean pathExists(int[][] puzzle, Position start, Position end) {
// your code goes here
}

1. Write a function that removes the duplicate of a collection of numbers and returns the number of elements remaining in the collection after the duplicates have been removed. You must ensure that duplicates are actually removed from the list.

Example #1

Input
{1, 1, 5, 3, 8, 3, 7, 32, 32}

Output
6

Example #2

Input
{21, 10, 24, 2, 21}

Output
4

int removeDuplicates(List numbers) {
// your code goes here
}

Problem:
8 balls, where 7 have equal weight, one does not. Find minimum times to use a scale to find ball that is not equal weight.

Interviewer answer: weight 6 balls. Choose balls from lighter side. Total two attempts. This is the average case but not the best case.

This is not true in all cases and the interviewer did not see this...

Best case:
Pick two balls. One may weight less, so the lighter ball is found with one attempt. This is the best case.

Worst case: If first two balls are equal, weight 6 balls. Choose balls from lighter side. Weight again. Total three attempts.

Given a string which only contains lowercase. You need delete the repeated letters only leave one, and try to make the lexicographical order of new string is smallest.
i.e:
bcabc
You need delete 1 'b' and 1 'c', so you delete the first 'b' and first 'c', the new string will be abc which is smallest.

ps: If you try to use greedy algorithm to solve this problem, you must sure that you could pass this case:
cbacdcbc. answer is acdb not adcb

I can't solve this problem well and the interviewer said that you can scan the string twice. First scan is do some preprocess, and the second is to get the answer, but I really can't come up this idea.

You are given a list of n float numbers x_1, x_2, x_3, ... x_n, where x_i > 0.
A traveler starts at point (0, 0) and moves x_1 metres to the north, then x_2 metres to the west, x_3 to the south, x_4 to the east and so on (after each move his direction changes counter-clockwise)
Write an single-pass algorithm that uses O(1) memory to determine, if the travelers path crosses itself, or not (i.e. if it's self-intersecting)
e.g.
2 1 1 2 -> crosses
1 2 3 4 -> doesn't cross

You have given an array and you want to find an integer k so that the sum of the distances from k to each of the n integers is minimized. Define distance between two integers a and b as |a−b|3.

A multiset or a bag is a collection of elements that can be repeated. Contrast with a set, where elements cannot be repeated.
Multisets can be intersected just like sets can be intersected.

Input :

A = [0,1,1,2,2,5]
B = [0,1,2,2,2,6]

Output :
A ∩ B = C = [0,1,2,2]

Input :
A = [0,1,1]
B = [0,1,2,3,4,5,6]

Output
A ∩ B = C = [0,1]

Write a function to find the intersection of two integer arrays in that way ?

"Smart substring"
Write a function that takes maximum 30 characters from a string but without cutting the words.

Full description:
"Featuring stylish rooms and moorings for recreation boats, Room Mate Aitana is a designer hotel built in 2013 on an island in the IJ River in Amsterdam."

First 30 characters:
"Featuring stylish rooms and mo"

Smarter approach (max 30 characters, no words are broken):
"Featuring stylish rooms and"

Find the nth Fibonacci Prime, in the shortest code

Billions of 2 digit number is coming from stream and you have a variable avg. which store only 2 digit number that means you cant store 2 number in any temp variable also.calculate avg on incoming stream

A string contains a-z, A-Z and spaces. Sort the string so that all lower cases are at the beginning, spaces in the middle and upper cases at the end. Original order among lower and upper cases needs to remain the same. For example: a cBd LkmY becomes ackm BLY. Is there a way in O(n) without extra space?

I came across this problem online.

> Given an integer:N and an array int arr[], you have to add some
> elements to the array so that you can generate from 1 to N by using
> (add) the elements in the array.

Please keep in mind that you can only use each element in the array once when generating a certain x (1<=x<=N). Return the count of the least adding numbers.

For example:

N=6, arr = [1, 3]

1 is already in arr.

add 2 to the arr.

3 is already in arr

4 = 1 + 3

5 = 2 + 3

6 = 1 + 2 + 3

So we return 1 since we only need to add one element which is 2.

Can anyone give some hints?

Check if two integers are equal without using any comparison operators.

Find how many numbers of length n are there such that each number is at least 4 smaller/greater than the number before and after it.

Eg: if n = 5, such numbers are 39518, 15951, etc.

There are three closed doors. Behind two of them there are donkeys, behind the third one there is a Mercedes-Benz. (Your task is to get the Mercedes, not the donkey).
You are asked to choose one of the doors. Once you have chosen, they open one of the remaining two doors with the donkey. Now there are two doors left: one you chose and the other one. To maximize your chance of getting the Mercedes, should you keep your choice or switch to the other door?

write a program how many squares in chessboard ?

Implement hashtable put function in C++ without using STL stuff.

Given a matrix containing 0 and 1. Consider 1 as 'Land' and 0 as 'Water'. Find out the number of 'Islands' in the matrix. That is, set of all adjacent 1 will make up for an island.

For example:

[ 0 1 1 0 1 ]
[ 1 1 1 0 0 ]
[ 0 0 0 1 1 ]
[ 1 0 0 1 0 ]

This problem has 4 islands. ( consider set of 1s, vertically, horizontally and diagonally ).

Please provide Oracle SQL and PLSQL questions

Suppose you have strings read in from a stream, e.g., '()(,)(())'. Detect if the parenthesis pair up correctly.

Part 1: How would you use threads to solve the problem?

Part 2: He then gave me an iterative solution and asked how the problem can be done distributively across multiple components.

Given a hashmap, HashMap<String,List<String>> with the following data:

A: B,C
B: X Y
X: Z
Y: Z

Expected output is an array of the dependencies. I initially started with Breadh-first search for simplicy, which had running O(|V|+'E') and space O(|V|). The interviewer said depth-first search is better; I don't see how DFS is better, because it requires recursion.

Part2: He then said my solution is functionally correct and then introduced a circular dependency and asked how to resolve it. I said using a visited hashset will detect a circular dep. He said it's not quite right and there a few approaches.

Given a string of english characters. Find the character that appears only once. I used arr[256] to store a count of each character. Then, iterate over the array to find the first non-dup, a[iter+'a']==1. The interviewer thought that storing a[iter]='x' (dup) and a[iter]=<index> was a better solution to avoid running a second pass over the string. In my mind, I disagreed using the array index, one can find the character that appears only once. The interviewer persisted, and told me to think about it.

Write a function which takes a BST and then "flattens" it (converts in-place into new BST), so all the nodes have only right child and no left.
Example:

10
   /   \
  5   15

Output:

5
  \
  10
    \
    15

You are given an array representing integer. Write a function which increments this integer.
Example: input [1,2,3] (represents 123) -> output [1,2,4]

A single-elimination tournament with 64 teams. Before the tournament, fans construct fantasy brackets for their tournament predications. Design a data structure for storing fan brackets and algorithm to score their brackets against a winning bracket. Assume we will then need to quickly score a player’s predictions (1 point per successful round prediction) and your solution should be optimal enough to handle millions of fan brackets with minimal data.