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

Efficient Network
There are n computer systems connected together to form a network. The network can be represented as a rooted tree (rooted at master computer 1), where the connections are described using two arrays connect_from[]and connect_to[]. Each pair (connect_from[i], connect_to[i]) denotes an undirected edge between the two computers. Additionally, each computer has a value assigned to i t denoted by the array computer_val[].

In order to maximize the throughput of the network, certain inefficient systems can be removed. In one operation, any computer node can be chosen, and all computer nodes in its subtree including this node can be removed from the network. Let the number of such operations appfied be num_ops.

For a given parameter k, the efficiency of the network after num_ops operations is calculated as: (sum of values of all remaining computer nodes - k * num_ops). Find the maximum possible efficiency after applying some (possibly zero) operations optimally.
Note: The node values can be negative.

Example
Consider the number of computers to be connect_nodes = 4, and their connections to be connect_from = [1, 2, 3], connect_to = [2, 3, 4]. Also, consider the node values to be computer_val = [3, -7, -8, -9] and the given parameter to be k = 5.
The given network cån be represented as: Show More

Subsequence Sort

Given a binary string binary consisting of characters '0' and '1' only, perform the following 0
or more times.
· Choose any subsequence, sort the subsequence, and replace the original subsequence with the sorted sequence.
Next, there is an array of strings, arr, of length n, where each string has length / binary/ and consists of characters '0', '1' and '?'. Each '?' characte r can be replaced with either '0' or '1' . For each string in arr, after replacing each ?' character with either '0' or '1', determine if it is possible to rearrange binary using the operation described any number of times. If it is possible, store "YES" as the corresponding answer, otherwise store "NO", both without quotes.

Note:

· A string a is a subsequence of a string b obtained by deletion of some number (possibly, zero or all) of characters without changing the order of the remaining characters.
· Each computation is independent of the others. That is, the string binary is in its original state at the beginning of each array element.

Example
Consider binary = "110100", and arr = ["?110?1","111 ??? "].
- arr[0] = "?110?1"can be converted to "011001"by appropriate replacement of ? characters. This
string can be obtained from binary as follows:
- Choose the subsequence of indices {0,2}, and sort this subsequence, binary becomes "011100".
- Choose the subsequence of indices (3, 4, 5} and sort this subsequence, binary becomes "011001",
which equals arr[0].
: The answer for this element is "YES".
- It is not possible to convert string binary to arr[1] so the answer for this element is "NO".

Return ["YES", "NO"], without quotes. Show More

Break The Bricks

There are n bricks arranged in a row at positions numbered from 1 through n, inclusive. There is an array, newtons[n], that contains an integer indicating the number of newtons required to
smash a brick., (A newton is a unit of force.)

There are two hammers, one big and one small. The big hammer can smash any brick with one blow. The small hammer reduces the newtons require d by 1 for each blow to a brick. For example, a brick requires 3 newtons of force. It will take 1 blow with the big hammer, or 3 blows with the small hammer to smash it. There is a limit to how many times the big hammer can be used.

Determine 3 values:
1. the minimum number of blows to smash all the bricks
2. the 1-based indices of the bricks smashed by the big hammer, sorted ascending
3. the 1-based indices of the bricks smashed by the small hammer, sorted ascending

Return the values as a 2-dimensional integer array, [[total hits], [big hammer hits], [small hammer hits]]. If a hammer is not used, its index array should be [-1].
Example
bigHits = 0
newtons = [2]
The big hammer cannot be used. The small hammer takes 2 blows to smash the single brick
at index 1. The return array is [[2], [-1], [1]].

bigHits = 4
newtons = [3, 2, 5, 4, 6, 7, 9]
In this case, it is best to use the big hammer on bricks at sorted indices [3, 5, 6, 7], using 4 hits to
smash them all. The small hammer is used on sorted indices [1, 2, 4] which have newtons of 3, 2, and 4. It takes a total of 3 + 2 + 4 = 9 hits with the small hammer. The total blows required = 4 +
9 = 13. The return array is [[13], [3, 5, 6, 7], [1, 2,

Function Description
Complete the function breakTheBricks in the editor below.

breakTheBricks has the following parameters:
int bigHits: the maximum blows with the big hammer
int newtons[n]: an array of distinct integers representing newtons required to smash each brick Show More