CareerCup

Design an airport service that will be used to allocate a free runway when the plane is about to land. Data structure for the same. What if the runway is not available? Message passing between control centre and the plane. Focus on low-level design and code. Can the same runway be alloted to two different planes (locking)? Database storage needed?

How to find if a Binary tree has an odd number of nodes without using node count? Binary tree does not have to be balanced

C program for the given two array as point of x and y
int x[] = { 2,3,2,4,2};
int y[] = {2, 2, 6,5,8}; count the pair
maximum area coverd in x y plane
Ouput:3
From the above input there are five coordinates possible (2,2)(3,2)(2,6()(4,5)and (2,8) in which (2,2)(2,6)(2,8)that is three coodinaters covers the maximum area in x y plane
Input: x[] ={1,2,3}
Y[] = {1,2,3}
Output: 1
there are three coordinates (1,1)(2,2)(3,3)in which only one coordinates covers maximum distancethat is (1,3)

Program to print last element of matrix by traversing a matrix by anticlockwise starting from cell(1,1) and skiping alternate.
Ex:
Input:1 2 3 4
2 4 5 1
7 9 6 2
3 5 2 7
Output: 5
Start traversing matrix from cell(1,1) skip next row element go to 3 row element again skip 4 element go to bottom of second column .....up to last element and print only last element.
If Input: 1 2
3 4
Output: 2
Input:1 2 3
4 5 6
7 8 9
Output: 5

Find numbers that formed from sring

Find the indices of all anagrams of a given word in a another word.
For example: Find the indices of all the anagrams of AB in ABCDBACDAB (Answer: 0, 4, 8)

Write AWS lambda function to fetch data from on premises oracle db and migrate to aurora db.

I tried :

var oracledb = require('oracledb-for-lambda');
var os = require('os');
var fs = require('fs');
'use strict';

str_host = os.hostname() + ' localhost\n';

fs.appendFile(process.env.HOSTALIASES,str_host , function(err){
    if(err) throw err;  
});

Can someone show me , i have table with same columns present in oracle db as well as aurora db i want to map form oracle to aurora. How to write it in java or python using aws lambda.

Design a data scrubber.

Say a customer couldn't use Alexa with Philips light bulb. Now customer calls to Alexa/Amazon customer support they figure out the issue is not with Alexa it's with the Philips LED bulb.

Now amazon will redirect their customer call / chat to third party customer support (Philips in this case).

Now somehow we need prevent the possibility of third party customer support trying to exploit our customers. For ex: asking their bank accounts, credit card, Social Security number etc..

How will you do that for AMAZON level ?

You have oracle database table , and AURORA AWS table with same fields , write a java lambda function to migrate data from oracle table to aurora. Also it should be realtime, if a new record is added to oracle it should update aurora db table as well.

Given an array of edges between any two points in 2 dimensional space. A single edge is represented by the co-ordinates of two points it is connecting for example (2,3),(4,5) represents and edge connecting points (2,3) and (4,5).Find out the total number of squares possible if all edges are parallel to X or Y axis.
NOTE : Include overlapping squares, squares having one side in common and squares contained within another square. Co-ordinates can have float values.

Example below -
I have considered a very simple input and output combination to keep it short.
Input
{
(0,0),(0,3)
(0,0),(3,0)
(0,3),(3,3)
(3,0),(3,3)
}
Output : 1

Possible Approach : Create a map as below -

Key(Slope of Edge in Degrees) - Value(Array of Edges)
0 - {(0,0),(3,0)},{(0,3),(3,3)}
90 - {(0,0),(0,3)},{(3,0),(3,3)}

While inserting edges in the map, make sure the edges are sorted by max(x1,x2) first and then max(y1,y2).
Pick 2 edges from one slope let's say slope 0, then pick 2 edges from slope 90 and see if square is formed or not. If square not formed, then look at next 2 edges of slope 90 and so on.
Sorting here is an expensive operation.

Please share any better solutions.

Given a grid M x N cells having weight in each cell(any integer),
For every path from TOP-LEFT to BOTTOM-RIGHT, find the minimum weight you come across.(Minimum per path.)
Now from all those minimum weights, find the Maximum.
You can move in all 9 directions.

Is this a trick question?

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

Find a pair that equals to the given target from the list of given two lists.
example:
input:
target = 7
list1= [[1,2],[2,4[,[3,6]]
list2 = [[1,2]]

Output:[[2,1]]

Explanation: There are only three combinations [1,1],[2,1] and [3,1], which use a total of 4,6, 8 respectively. Since 6 is the largest use that does not exceed 7, [2,1] is the only optimal pair.

Example 2:
Input :
target = 10
list1 = [[1,3],[2,5],[3,7],[4,10]]
list2 = [[1,2],[2,3],[3,4],[4,5]]

Output;
[[2,4],[3,2]]

Prroblem: write an algorithm to calculate the minimum cost to add new roads between the cities such that all the cities are accessible from each other

int numTotalAvailableCities = 6;
int numTotalAvailableRoads = 3;
int[,] roadsAvailable = { { 1, 4 }, { 4, 5 }, { 2, 3 } };
int[,] costNewRoadsToConstruct = { { 1, 2,5 }, { 1,3,10 }, {1,6,2} ,{ 5, 6, 5 } };
int numNewRoadsConstruct = 4;

public class MinimumCostToConstructNewRoad
    {
        public static int getMinimumCostToConstruct(int numTotalAvailableCities,
            int numTotalAvailableRoads,
            int[,] roadsAvailable,
            int numNewRoadsConstruct,
            int[,] costNewRoadsConstruct)

        {
            int totalCost = 0;
            bool[] Visited = new bool[numTotalAvailableCities];
            int[] Keys = new int[numTotalAvailableCities];
            int[] Parent = new int[numTotalAvailableCities];

            int[,] AdjMatrix = GetAdjecencyMatrix(roadsAvailable, costNewRoadsConstruct, numTotalAvailableCities);


            for (int i=0;i< numTotalAvailableCities;i++)
            {
                Keys[i] = Int32.MaxValue;
            }

            Keys[0] = 0;
            Parent[0] = -1;

            for(int i=0;i< numTotalAvailableCities-1;i++)
            {
                var u = FindMin(Visited, Keys);

                Visited[u] = true;
                for(int v=0;v< numTotalAvailableCities;v++)
                {
                    if(Visited[v]==false && AdjMatrix[u, v]!=Int32.MaxValue && AdjMatrix[u,v]<Keys[v])
                    {
                        Parent[v] = u;
                        Keys[v] = AdjMatrix[u, v];
                    }
                }

            }

           for(int i=1;i< numTotalAvailableCities;i++)
            {
                totalCost = totalCost + AdjMatrix[Parent[i], i];
            }
            return totalCost;
        }


        private static int FindMin(bool[] Visited, int[] Keys)
        {
            int min = Int32.MaxValue; int index = -1;
            for (int i = 0; i < Keys.Length; i++)
            {
                if (Visited[i] == false && Keys[i] < min)
                {
                    min = Keys[i];
                    index = i;
                }
            }
            return index;
        }


        private static int[,]  GetAdjecencyMatrix(int[,] roadsAvailable, int[,] costNewRoadsConstruct,int numTotalAvailableCities)
        {
            int[,] AdjMatrix = new int[numTotalAvailableCities, numTotalAvailableCities];

            for (int i = 0; i < numTotalAvailableCities; i++)
            {
                for (int j = 0; j < numTotalAvailableCities; j++)
                {
                    AdjMatrix[i, j] = Int32.MaxValue;
                }
            }


            int count = 0;
            for (int i = 0; i < roadsAvailable.GetLength(0); i++)
            {
                int start = roadsAvailable[i, count]-1;
                int end = roadsAvailable[i,count+1]-1;
                AdjMatrix[start, end] = 0;
            }

            for (int i = 0; i < costNewRoadsConstruct.GetLength(0); i++)
            {
                int start = costNewRoadsConstruct[i, count]-1;
                int end = costNewRoadsConstruct[i, count+1]-1;
                int cost= costNewRoadsConstruct[i, count + 2];

                AdjMatrix[start, end] = cost;
            }

            return AdjMatrix;
        }
    }

how would you debug a tablet with a part of its touch screen is broken.

Given a series of equations e.g. [A = B, B = D, C = D, F = G, E = H, H = C]
and then another series [A != C, D != H, ..., F != A ]

Check whether the equations combined is valid.

For the example given, your program should return 'invalid', because the first series implies that A = C, which contradicts the statement A != C in the second series.

Imagine you have a computer keyboard that has all the letters mismatched

example:
typing q gives you a
typing w gives you b

all 26 letters in the alphabet are there, but typing one letter will give you another one

you are asked to write an algorithm to find whatever word you tried to type and count how many cycles you did to find the word

a restriction was set you need to type the whole word every time, not go character by character

note: a graph was suggested to represent the letter mappings

How to find out distinct ngrams from a email_alias.
For instance xyz@gmail.com here the email_alias is xyz.for xyz if we want to find bigram then function should have input the email_id,and the number of grams lets say 2.
Than it has to return the distinct count of ngrams present in the email_alias.

You have two files in hdfs one having date range with two columns start date and end date and another having two column with date and visitors field. You have to write a spark code which gives date range having maximum no. of visitors using that two files.

Given an array which represents columns, find the position of two columns which when removed will trap the maximum amount of water. This is related to trapping raining water problem.

Given an unsorted array find the maximum distance between two elements satisfying the condition A[i] < A[j] where i < j. There will always be a solution.

For eg. 6, 9, 3, 2, 10, 2, 3

How should I prepare for the interview with Alexa team at Amazon?

Given max. travel distance and forward and backward route list, return pair of ids of forward and backward routes that optimally utilized the max travel distance.:

eg: max travel distance is : 11000
forward route list : [1,3000],[2,5000],[3,4000],[4,10000]
backward route list : [1,2000],[2,3000],[3,4000]

Result : [2,3] ...2 is from forward and 3 is from backward...total distance is 9000...no other combination is there which is >9000 and <=11,000.......0(n^2) solution is straight forward, thinking that sorting both might help.

Given an array, coin of size n, coin[i] denotes the no. of coins on the position i. Can move any number of coins from the position i to (i+1) or (i-1). What is the minimum no. of moves required to redistribute the coins, so that each position i has at least 1 coin ?
Note: Summation of total coins on the array is exactly n.

Given multiple input streams of sorted numbers of infinite size, produce a single sorted output stream.

(The size of all the input streams are unknown)

For eg.

Input Stream 1: 2,4,5,6,7,8...........
Input Stream 2: 1,3,9,12..............
Input Stream 3: 10,11,13,14........

Output Stream:
1,2,3,4,5,6,7,8,9,10,11,12,13...............

Group orders by items present in the orders.

Class Order{
String orderId;
List<String> items;
}

Given Order id and items:

O1: [A, B]
O2: [B, C]
O3: [D, E]

Output: [[O1, O2], [O3]]

Note: There can be more that 2 items in an order.

List<List<String>> implementhis(List<Order> orders){
}

Design an email client where you can only send emails to people who are present in your contact list. Build for only the following functionaliy
1) Send/Receive Emails
2) Add/Remove Contacts
3) See Inbox
4) See Sent Mail

Design a distributed LRU Cache.

Given a binary tree, find the closest LEAF node to the target.

What would be the sample class design of notification system?