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Houses in Hackerland
The city of Hackerland has many houses, each of which is connected via roads. There are house_nodes number of houses, numbered 0 to house_nodes - 1, where each pair of houses is connected and has a unique shortest path between them. Thus, the network of houses and roads forms an undirected tree structure comprising house_nodes nodes and (house_nodes - 1) edges. Each of the ed ges has a value denoted by val[i], which can either be 0 or 1.

To summarize, the overall tree is represented as follows:
house_nodes: the number of nodes
house_from, house_to: the arrays representing an undirected edge between house_from[i] and house_to[i] for 1 ≤ i ≤ house_nodes - 1.
val[]: the value of each edge in the tree, which can be either 0 or 1.

Problem Statement
Given the network of houses and roads, the task is to find the number of sequences of length k (h[1], h[2], ... h[k]) such that while visiting:
From house h[1] to h[2],
Then from h[2] to h[3],
And so on until reaching house h[k],
Using the unique shortest path between them, at least one edge with value '1' is visited. Show More

Modified Knapsack Problem

The Knapsack problem is a well-known problem in the field of computer programming and problem-solving. To make it more interesting, an interviewer uses a modified version of the problem.
Given n items, where the weight of the i-th item is 2^i, and the cost of the i-th item is cost[i], find the minimum amount needed to purchase the items such that the combined weight o f the purchased items is at least minWeight.

Example
Consider n = 5 ,cost = [2, 5, 7, 11, 25] ,minWeight = 26

One of the optimal ways to purchase the items is as follows:
Buy 2 units of the 0th item and 3 units of the 3rd item.
Total cost = (2 × 2) + (3 × 11) = 37.
Total weight = (2 × 2^0) + (3 × 2^3) = 26, which is at least minWeight.
Return the total cost of the items, 37.

Function Description
Complete the function getMinimumCost in the editor below.
getMinimumCost has the following parameters:
- int cost[n]: the cost of each item
- int minWeight: the minimum combined weight Show More

Question 2

Implement a Least Frequently Used (LFU) cache data structure of size cacheSize that handles two types of queries: GET and PUT.

A GET query attempts to retrieve the value of a given key.

If the key is present in the cache, it is returned.

Otherwise, it returns -1.

A PUT query updates or inserts a key-value pair into the cache.

When the cache is full, the least frequentl y used key is removed to accommodate the new key-value pair.

If there is a tie in the frequency of keys, then the least recently used key is removed.

Return an array of integers where each i-th element is the answer for the i-th GET query.

Example
Suppose
cacheSize = 1
q = 5
queries = ["PUT 1 1", "PUT 2 2", "GET 1"]

Only cacheSize = 1 element is stored in the cache. Show More

A forklift operator navigates products within an automotive parts warehouse. The dashboard displays a real-time map showing open and blocked sections as an n x m matrix of 1's (open) and 0's (blocked). The operator starts at the top-left corner of the map at warehouse[0][0] and aims to reach the bottom-right corner at warehouse[n-1][m-1].

Movements can only be made to the right or downward. Giv en the warehouse map, calculate the number of distinct paths from warehouse[0][0] to warehouse[n-1][m-1]. Return the result modulo (10⁹+7).

Example
warehouse = [ [1, 1, 0, 1], [1, 1, 1, 1] ]

The matrix below is drawn from the warehouse array, showing open and blocked sections of the warehouse. 1 indicates an open section, and 0 indicates a blocked section. It is only possible to travel through open sections, so no path can go through the section at (0, 2). Show More

1. Question 1
Given a chessboard of n rows (top to bottom) and n columns (left to right). In each move, a knight moves either:
2 column positions and 1 row position
2 row positions and 1 column position
In other words, a move is 2 steps along one axis and 1 step along a perpendicular axis.
Given a starting position A and ending position B, calculate the minimum number of moves needed by the k night to move from A to B if it is possible. If it is not possible, return -1. All moves must remain within the chessboard.

Example
n = 9
startRow = 4
startCol = 4
endRow = 4
endCol = 8

The chessboard has a size of 9 x 9.
Starts at the position (startRow, startCol) = (4, 4).
- Move 1 step up or down, then 2 steps right to reach either the position (3,6) or (5,6).
- Move 2 steps right and 1 step down or up as... Show More

The class uses a novel system where the success of an individual is assigned to a symbol. These symbols have the following precedence:

A > B > C > D > E > F

The symbols are collected and fed into the assessment robot. The success of the class is determined in the following way, with the output in green at the end:

"AAABBCDDEFF"

Sometimes it is ambiguous what the output is. In this case , the assessment robot observes the precedence given:

"AAABCCCDDEE" Show More

4. Question 4

Your colleagues often bring a few books to the office to read, then put them into shared book shelves, so other people have the chance to read it as well. After some days, the shelves have become messier and messier. As the office manager you are tasked to develop a function to sort them.

As the basic information of a book, the name, author and edtion will be recorded.
The fun ction will recognize different books as following: Show More

You are a part of the World of Wizards—a global society of magicians. It's your task to create a "warped-spell" that helps the society ensure the authenticity and secrecy of its members.

All the members meet once a month at a secret club. In order to ensure the authenticity of members, each member is sent a "secret" number of 1-7 digits, 10 days before the meeting.

On the meeting day, each m ember has to present a new "warped" number, which is made by casting a warped-spell on the "secret" received 10 days ago.

The "warped" number must have the following magical attributes:

1. Must be strictly 4 - 7 digits in length, i.e., numbers from 1000 to 9999999.
2. Must always be greater than the secret itself.
3. Must have mirror-like characteristics, as shown below: Show More

1. Question 1

You've just started as a trainer in Thoughtworks University, and you want to make a good first impression. You start investigating how to make it easier to organise the coding sessions. It turns out that trainers are spending a lot of their time finding out the average confidence of the participants.

The coding sessions are organised based on how confident the participants are with programming. This is a self-score rating on a scale of 0 to 9. To save having to count how many participants there are, the trainers always prepend this number to the list of participant confidence ratings.

You also find that coding sessions are done in pairs. When there are an odd number of participants, the overall confidence can be determined using the following flow chart: Show More

The Amazon warehouse receives a multitude of packages every day, each assigned a unique identifier from 1 to n. The warehouse manager must sort the packages, not by their identifiers, but rather through a specific process defined by a permutation sorterOrder that ensures optimal processing.

Initially, the number of sorted packages, sortedCount, is zero. In each operation, the manager sifts thro ugh the packages from left to right. If the current package's identifier aligns with the next one to be sorted (i.e., sorterOrder[i] = sortedCount + 1), the manager sorts it and increments sortedCount by one. If the current package is not next in the sorting sequence, the manager overlooks it.

Determine the number of operations required by the manager to sort all the packages. One operation indicates a complete check from the first package to the last.

Note: A permutation is a sequence consisting of integers from 1 to n, of length n, containing each integer exactly once. For example, [1, 3, 2] is a permutation, while [1, 2, 1] is not.

Example 1:
n = 5
sorterOrder = [5, 3, 4, 1, 2]

Initially sortedCount = 0. In the first operation, the manager does the following: Show More