CareerCup

Given a binary tree, how do you serialize and deserialize. Remember it is not BST it is a general binary tree which can also have duplicate elements.

Find the largest repeating sub-string in a string.
ex: banana
ans is: ana

You are given a log file with the bandwidth information of users in several lines.
Bandwidth info for a certain user may be repeated.
User:A Bandwidth:50 CountryCode:IND
User:B Bandwidth:60 CountryCode:USA
User:A Bandwidth:70 CountryCode:IND
(i) Find total amount of bandwidth consumed per user
(ii) Suppose there are 4 country codes, for every country code, find the top 5 users which consumed maximum bandwidth sorted.

Given a matrix. Convert it into a linked list matrix such that each node is connected to its next right and down node.

Ex:
1 2 3
4 5 6
7 8 9

Output:
1->2->3->NULL
| | |
v v v
4->5->6->NULL
| | |
v v v
7->8->9->NULL
| | |
v v v
--NULL-

This is my code.

class Ideone
{
	public static void main(String args[]) throws Exception {
		int arr[][] = { { 1, 2, 3 }, 
				        { 4, 5, 6 } };
		LList op = convert2DArrintoList(arr, 0, 0);
		System.out.println(op);
	}
 
	public static LList convert2DArrintoList(int arr[][], int col, int row) {
		if (col >= arr[0].length || row >= arr.length)
			return null;
		return new LList(arr[row][col], convert2DArrintoList(arr, col, row + 1), convert2DArrintoList(arr, col + 1, row));
	}
 
	static class LList {
		LList(int data) {
			this.data = data;
		}
 
		LList(int data, LList down, LList next) {
			this.data = data;
			this.down = down;
			this.next = next;
		}
 
		LList() {
			this.data = Integer.MAX_VALUE;
		}
 
		@Override
		public String toString() {
			return " " + this.data + " ";
		}
 
		int data;
		LList next;
		LList prev;
		LList rand;
		LList down;
	}
}

Are there better ways of doing it?

// Create a numeric binary tree structure/classes that have left and right children and an integer numeric value.
// Write a function 'isBalanced' for a node that returns true if the sum of all the children on the left is equal
// to the sum of all the children on the right.

//Example:
// [12] [12].isBalanced() -> True. [3, 3]
// / \
// [3] [1] [1].isBalanced() -> True. [2, 2]
// / \
// [2] [0]
// / \
// [2] [0]
// - Part I: setup and isBalanced() function
// - Part II: implement “allBalancedNodes()” <— given a node, finds all balanced children
// allBalancedNodes(12) -> returns a list of balanced nodes: { [1], ... }

Given a fully connected graph with n nodes and corresponding values. One node can interact with other node at a time, to replace/ignore/add its value to other node’s value. Assuming this operation takes 1 unit of time, how much time would it take for all the nodes to have value equal to sum of all the nodes.

Examples : Given a graph with values {1,2,3,4}, find total time it takes, such that all nodes have value as 10.

I am assuming it can be done in O(N).It will take basically two traversals, one for calculating the sum of values of nodes(first traversal), other for replacing the value of the nodes(second traversal).

It will take 2*(no of nodes) time.

Are there any better ways possible ?

Design amazon's frequently viewed product page.

Design a ESPN like system. Ensure scaling and availability. Also one should get all details like score of a player, no. of mtches etc.

..

Design a FIDS(Flight Information Display System)

1. Consider most important classes & ignore Interfaces as of now
2. FIDS is not about reservation system but the dasboard to display
3. the information will look like:

DEPARTURES
----------------------
Attributes:
STD Airline Flight Destination/Via CheckInCounter# Gate Status ETD

Values :
12:50 KingFisher 6E352 Hyderabad A-B 23 Check-In Open 13:15

ARRIVALS
-----------------------
Attributes:
STA Airline Flight# Destination/Via Gate Status ETA

Values :
12:50 KingFisher 6E352 UK/Mumbai Terminal2 Landed 13:15

Given a list of employees and their bosses as a CSV file , write a function that will print out a hierarchy tree of the employees.

Design Distributed Web Crawler.

Phone Interview Amazon, Seattle
I. Get the sum of all prime numbers up to N. primeSum(N).
Follow-up: If primeSum(N) is frequently called, how to optimize it.

II. OODesign Parking Lot

// Imagine you have an array of N messages which is consistently having new messages added to it.
// When you loop through the array, the messages are guaranteed to be ordered chronologically by timestamp.
// Write some code that loops through the array of messages and when a unique user_id has two messages within one second of each other, call a method too_fast that takes in two parameters, the first is the older message, the second is the newer message.
// In the message examples below we would expect to call the too_fast method with the first and third message, and then again with the third and fifth message.

// message example 1 = { "container_id": 123, "item_id": 456, "success": true, "timestamp": 1499351653, "user_id": 789 }
// message example 2 = { "container_id": 111, "item_id": 222, "success": false, "timestamp": 1499351654, "user_id": 333 }
// message example 3 = { "container_id": 444, "item_id": 555, "success": true, "timestamp": 1499351654, "user_id": 789 }
// message example 4 = { "container_id": 123, "item_id": 456, "success": true, "timestamp": 1499351655, "user_id": 999 }
// message example 5 = { "container_id": 123, "item_id": 456, "success": true, "timestamp": 1499351655, "user_id": 789 }

// Within the loop you can access attributes by using message.getContainerId() or message.getItemId for example, message.getTimestamp()

write bash code to determine if the first number in the string is greater than 1000

STR="count ------- 43952 (1 rows)"

I have a Amazon Phone interview for sr. business analyst They provided a collabedit link for the interview stating that we may ask Basic programming and SQL questions.

Can someone having this experience from past help me understand what kind of questions I can expect. I honestly am a BA, PM professional with not a lot of exposure to coding or SQL. Some guidance will help me prepare better. Are the questions asked in SQL basic or quite intricate? Please advise

The memmove() function copies n bytes from memory area src to memory area dest. The memory areas may overlap: copying takes place as though the bytes in src are first copied into a temporary array that does not overlap src or dest, and the bytes are then copied from the temporary array to dest.

I've got these trees of integers; they're like regular trees, but they can share nodes.
I need to know if any branch of this tree sums to 100.
7
/ \
8 6
/ \ / \
2 3 9
/ \ / \ / \
5 4 1 100

Follow up question was how would you change the code to handle negative numbers

I've got these trees of integers; they're like regular trees, but they can share nodes.
I need to know if any branch of this tree sums to 100.
7
/ \
8 6
/ \ / \
2 3 9
/ \ / \ / \
5 4 1 100

Follow up question was how would you change the code to handle negative numbers.

Find distance between any two nodes of binary tree and binary search tree.

There is a conference room. N people are joining the conference. You have the start time and end time of each of them visiting it. You are asked to determine the maximum number of people that can be inside the room.

Example – Four people are visiting the conference
Person A B C D
Start (hour) 1 3 2 5
End (hour) 4 5 7 10
Answer will be – 3

Identifying if all the elements of a set (in enterity) is present in a list of sets.

For example checking for set1 = {1,2} in {1,2,3}, {5,6} should return true as {1,2} is present in {1,2,3}. Similiary it will be true for {1,2,8,9}, {1,2,4}

But checking for {1,2} in {1,5,6}, {2,3,1} should return false as {1,5,6} does not contain all elements of {1,2} 2 is missing

Given string a and string b, find all the occurences of the anagrams of a in b.

How would you store very large numbers that can't be store in a regular Integer or BigInteger, and make calculations

Design an application for people to find a place near them where they can join a team to play their favorite sport. Exp. Soccer teams open to join that are scheduled to play at a certain time and place. The application would search for the available teams to join within certain area playing within some given time period,

[System Design] Design a mobile application to provide nearest parking lot locations and availability?

[System-Design] Design air traffic control system?

Lazy Bartender :

There are N number of possible drinks.(n1,n2..)
Has C number of fixed customers.
Every customer has fixed favourite set of drinks.
Bartender has to create least possible number of drinks
to suffice need of all the customers
Example:
Cust1: n3,n7,n5,n2,n9
Cust2: n5
Cust3: n2,n3
Cust4: n4
Cust5: n3,n4,n3,n5,n7,n4

Output: 3(n3,n4,n5)

Given transactions between group of friends. How to minimize the number of transactions by eliminating redundant cash flow paths?

Write second most repeating word in a string
eg aaa bbb ccc aaa bbb aaa
answer - bbb