CareerCup

Given a dictionary of words and a string pattern. Output the count of words that match the string pattern in the dictionary.
Eg. Dictionary: [cat, rat, mat, apple, boy, bat]
String pattern: ?at
Output: 4 (because cat, rat, mat, bat matches the string pattern)

Given any two nodes in a binary tree, find the path from 1st node to another, and tell if the path is a straight line, or there are turns on the line, find number of turns.

Find the maximum difference between any combination of child and parent node in a given binary tree. Here child node can be any level below parent node, but should be in the same sub tree starting from parent node.

Design Truecaller. Both HLD and LLD.

Given a chessboard, find minimum number of moves for a knight to reach from source to destination.

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.

Given a Singly Linked list, Update the second half of the list such that n-th element becomes sum(1st + nth) element, (n-1)st element becomes sum(2nd + n-1st) element and so on. Eg: 2->3->4->5->6 => 2->3->(4+4)->(5+3)->(6+2)

Given an Infinite stream of strings as AAAAABBBCCDDDEEE… How will you arrange characters so that string become unique without duplicates .

Return true if it is possible to arrange else return -1.

Ex . AAABBCCDEF – O/p ABABCDCEF : Possible . AAAAAAAAAAAAAAAAAAAAAAB : Not possible

Given an array of integers, replace every number with the next higher number to its right. If a number can’t be replaced, we leave it as-it is.
For example, the list: 5, 2, 1, 4, 6, 7 needs to be changed to 6, 4, 4, 6, 7, 7.

Given two unsorted arrays A, B. They can contain duplicates. For each element in A count elements less than or equal to it in array B

Examples:

Input : A = [1, 2, 3, 4, 7, 9]
B = [0, 1, 2, 1, 1, 4]
Output : [4, 5, 5, 6, 6, 6]

Write a logic to print the elements of 2D matrix in a spiral way?

for eg if int[][] matrix = {{1,2,3,4}{5.6,7,8}{9, 10, 11,12}};
The output should be 1 2 3 4 8 12 11 10 9 5 6 7
The interviewer asked me to implement a recursive algorithm.

Given a continuous stream of numbers, write a logic to find k maximum numbers at any given point of time where k is fixed?

Given some set of points in each quadrant of a 2D graph and two edges at a fixed angle, find the minimum angle at which the edges would cover maximum points between them?

I was confused on how to start and interviewer hinted me to consider each point at some angle from base (say 0) and continue finding all points which lies within the fixed angle.

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.