Coding Interview Questions
 0of 0 votes
Multi level cache system design with different storage in each level.
Read Operation : – Minimum time to read a particular key from cache system. This should be followed by writing the key in all levels above it. Eg. if “key” is found at level ‘i’, add this key to cache present at 1 to i1 level.
b. Write Operation: – Any write Operation should write in cache of all levels.
You can choose any algorithm for cache management like LRU, MRU.
 0of 0 votes
Because Ethereum smart contracts are deployed publicly, anyone with the right tooling can read their contents.
Furthermore, people can access any state the contract specifies. Knowing that people have access to your
validation code, how do you write the contract so that somebody *must solve the problem. (*it should be near
impossible or significantly computationally expensive to derive the answer from your contract code)
 0of 0 votes
Ethereum is a blockchain that can run arbitrary programs. Write an ethereum program (i.e. contract) that will send 0.1 ETH (a bounty) to the first person who gets the correct answer to the above "100digit"
question.
 0of 0 votes
Given a wall, which is made up of two types of bricks (Porus / opaque ). Porus bricks allow water pass through them. Opaque won't. Find whether water reaches to ground, if there is any rainfall.
Water can flow from top to bottom, diagonally, horizontally as well. Only flowing from bottom to top is not possible.
 1of 1 vote
Given a string as input, return the list of all the patterns possible:
'1' : ['A', 'B', 'C'], '2' : ['D', 'E'], '12' : ['X'] '3' : ['P', 'Q']
Example if input is '123', then output should be [ADP, ADQ, AEP, AEQ, BDP, BDQ, BEP, BEQ, CDP, CDQ, CEP, CEQ, XP, XQ]
 0of 0 votes
Given a singly linked list, Your task is to remove every Kth node. The task is to complete a method deleteK that takes two argument, head of linked list and an integer k.The method returns the head of the new linked list. There are multiple test cases. For each test case, this method will be called individually.
 1of 1 vote
I am surprised by this GS question.I thought this is one of the classic number theory partition problem which is so hard that the best algorithm is approximation one.
Given value, find all possible combination of ways which equals to that sum.
 0of 0 votes
Google Fucked up question.
Given a random list of appointments (Start Date , End Date). Find all the appointments that are colliding.
This pretty easy looking question screwed me up today.There are tons of edge cases, I couldn't complete em all and 45 minutes pass like 15 minutes while explaining and coding same time.
 1of 1 vote
Imagine a computer where you have no "/" (divide) operation. All other operations are implemented including addition, multiplication, binary shift etc. Implement function div(int a, int b) using available operators only.
 0of 0 votes
I was given this question recently in an interview.. There are three threads and a counter that will increase from 1 to 100. Catch is that thread 1 increments counter from 1 to 20. Thread 2 increments from 21 to 80. Thread 3 increments from 81 to 100.
 0of 0 votes
N different couple go to cinema with 2N different seats. They take their place randomly. You could make swap operations. Write a code for given input what is the minimum number of swap operations for sitting all couples with their partners? Additionally, be sure that no one swaps more than 2 times.
 1of 1 vote
Given an array of sorted integers and find the closest value to the given number. Array may contain duplicate values and negative numbers.
Example : Array : 2,5,6,7,8,8,9
Target number : 5
Output : 5
Target number : 11
Output : 9
Target Number : 4
Output : 5
 0of 0 votes
Write a function to convert a String of ip address to hex
eg: ip is 197.27.11.11 = 0xC51BBB. The conversion to hex has to be done without preexisting library function. like String.format() etc.
 0of 0 votes
An web service maintains logs (suppose there are multiple log files per day) of all ip address which has requested service. If there is a DOS attack on the server find all ip addresses that has sent more number of requests and block them. Can this be done without writing any function in higher programming language?
What would the function look like if written in some language like C, Java etc?
Can this be done in Time optimized and space optimized manner?
 0of 0 votes
You are provided with 2D char array. You have to provide the 2D char array as response which contains the multiplication od the input array. For eg: input=> {{a,b},{c,d}}, output => {{a,c},{a,d},{b,c},{b,d}}
 7of 7 votes
aa
 0of 0 votes
A company's organizational structure is represented as
1: 2, 3, 4
In the above employees with id 2, 3 and 4 report to 1
Assume the following hierarchy.
1: 2, 3, 4
3: 5, 6, 7
5: 8, 9, 10
Given an employee Id, return all the employees reporting to him directly or indirectly
 0of 0 votes
Given a array of integers there is one that is repeated several time. How would you compute the length of the sequence of repeated elements.
Assuming the initial array is sorted can you do better than O(n) both for spatial and temporal cost?
 0of 0 votes
Implement power function. The function should take two numbers as input (e.g. 2,3) and return 8 as output
See link below for hints and answer https://baquerrizvinotes.blogspot.in/2017/05/howtocrackamazoncomtechnical.html
 0of 0 votes
You are given an array of nodes where each node consists of node name, isValid flag, and parent Node index. so, this array actually represents a tree(forest). where root node has 1 as its index for the parent node. rest all node have their parent's index value.
You will be given this array and an index. You have to cut down the subtree from the index. Cutting down a tree means, making all the nodes of that subtree false(Isvalid flag).
He was expecting O(N) solution.
 0of 0 votes
You are given an array of values, (not necessary integers or positives) and a value. You have to print all the pairs whose sum is given value. Write a general method which can accept integers, float, doubles, long, or any other thing where this make sense.
 0of 0 votes
A college student's record contains the following:
1. Name
2. Age
3. Subject(s)
4. Marks
5. ID
The student can choose from English, Mathematics and History as subjects. A student can choose one, two or all of the subjects.
The requirement is to search for students who have scored marks more than X in a certain subject. Which Data Structure would you use and how would you solve this problem in an optimal manner?
 0of 0 votes
Q 2. You are given a chess game board of size NxN. You have find out positions(i,j), where you can place N queens so that, none of the queens can kill each other without making their first move.
 0of 0 votes
Implement a Message Broker, with Publisher and Subscriber. There can be multiple Topic or Subject in Message Broker.
 1of 1 vote
Given an array of integers greater than zero, find if it is possible to split it in two (without reordering the elements), such that the sum of the two resulting arrays is the same. Print the resulting arrays.
 2of 2 votes
Iterate over a singly linked list backwards. Call print on each node.
Example: The list A>B>C should print as
"C B A"class Node { public Node next; public String value; }
There are 4 solutions
1) recursive
2) iterative with O(n) memory
3) iterative with O(1) memory and O(n²) runtime
4) iterative with O(1) memory and O(n) runtime (for this solution the initial list may be modified)
Explain all 4 solutions and write the code for solutions 3 and 4
 1of 1 vote
You are given an array of integers.
Write an algorithm that brings all nonzero elements to the left of the array, and returns the number of nonzero elements.
The algorithm should operate in place, i.e. shouldn't create a new array.
The order of the nonzero elements does not matter. The numbers that remain in the right portion of the array can be anything.
Example:
given the array [ 1, 0, 2, 0, 0, 3, 4 ],
a possible answer is [ 4, 1, 3, 2, ?, ?, ? ], 4 nonzero elements, where "?" can be any number.
Code should have good complexity and minimize the number of writes to the array.
 1of 1 vote
Cross the street
ABC Company is involved in the logistics business.
The company has many outlets and stockyards in a city. The city is like an
N
×
M
N×M grid. We consider a single cell of the given grid to be a single block in the city. The stockyard is at the upperleft corner and the outlet is located in the lower right corner. Everyday, one of the employees has to travel from the upper left to the lower right corner for supplies. Each block in the city has a height, where the height of the block located at position (i,j) in the grid is equal to
A
[
i
]
[
j
]
A[i][j]. The company wants to change the heights of some of the blocks, so that the employee can enjoy a highspeed drive from the stockyard to the outlet. But this change comes at a certain cost.
Specifically, if they change a block height from x to y, then they must pay exactly

x
−
y

x−y dollars. Please help them find the minimum cost, such that by spending that specific amount, they can get a path from stockyard to the outlet with all blocks along the path having the same height.
In a single move, the employee can move from a block to any of its adjacent blocks. Note that during this journey, the employee is allowed to move in all four directions, fulfilling the condition that he never goes out of the grid at any point in time.
Input :
First line contains two positive integers N and M  number of rows and columns in the city. Then, N lines follow, each containing M integers, where the
j
t
h
jth integer on the
i
t
h
ith line denotes
A
[
i
]
[
j
]
A[i][j].
Output :
The first and only line of output should contain minimum cost.
Constraints :
1<= N, M <=100
1<= height of blocks <=100
Sample Input
5 5
1 1 1 1 1
9 9 9 9 1
1 3 3 3 1
1 9 9 9 9
1 1 1 1 1
Sample Output
6
Explanation
Optimal path taken by the employee will be : (1,1) > (1,2) > (1,3) > (1,4) > (1,5) > (2,5) > (3,5) > (3,4) > (3,3) > (3,2) > (3,1) > (4,1) > (5,1) > (5,2) > (5,3) > (5,4) > (5,5) The height of each block along this path can be changed to
1
1, at a total cost of
6
6. There is no way to get a cost less than this.
 1of 1 vote
Write a program to reveres string from intervals
 1of 1 vote
Find the maximum consecutive 1's in an array of 0's and 1's.
Example:
a) 00110001001110  Output :3 [Max num of consecutive 1's is 3]
b) 1000010001  Output :1 [Max num of consecutive 1's is 1]