SDE - 1

Given an array of numbers, find the maximum sum of any contiguous subarray of the array.

For example, given the array [34, -50, 42, 14, -5, 86], the maximum sum would be 137, since we would take elements 42, 14, -5, and 86.

Given the array [-5, -1, -8, -9], the maximum sum would be -1.

Follow up: Do this in O(N) time.

You have been given 'N' ropes of different lengths, we need to connect these ropes into one rope. The cost to connect two ropes is equal to sum of their lengths. We need to connect the ropes with minimum cost.

The test-data is such that the result will fit into a 32-bit integer.

You have been given a board where there are '2' rows and 'N' columns. You have an infinite supply of 2x1 tiles, and you can place a tile in the following ways:

1. Horizontally as 1x2 tile
2. Vertically as 2x1 tile

Count the number of ways to tile the given board using the available tiles.

Note :

The number of ways might be large so output your answer modulo 10^9 + 7.

Here an example of tile and board for 'N' = 4 :

You have been given an Encrypted String where repetitions of substrings are represented as substring followed by the count of substrings.

Example: String "aabbbcdcdcd" will be encrypted as "a2b3cd3".

You need to find the 'K'th character of Decrypted String. Decrypted String would have 1-based indexing.

Note :

Input string will always be lowercase characters without any spaces.

If the count of a substring is 1 then also it will be followed by Integer '1'.
Example: "aabcdee" will be Encrypted as "a2bcd1e2"
This means it's guaranteed that each substring is followed by some Integer.

Also, the frequency of encrypted substring can be of more than one digit. For example, in "ab12c3", ab is repeated 12 times. No leading 0 is present in the frequency of substring.

The frequency of a repeated substring can also be in parts.
Example: "aaaabbbb" can also have "a2a2b3b1" as Encrypted String.

Given an array of distinct integers, find all the pairs having positive value and negative value of a number that exists in the array. Return the pairs in any order.

Note:

The pair consists of equal absolute values, one being positive and another negative.

Return an empty array, if no such pair exists.

You are given a list of ‘transactions’ between ‘n’ number of friends. who have to give each other money. The list consists of data of receiver, sender, and transaction.

Your task is to minimize the cash flow and the total number of transactions should also be minimum.

For example :

In figure 1 : friend-1 has to pay 2000$ to friend-2, and 4000$ to friend-3 and friend-2 has to pay 3000$ to friend-3.

In figure 2 : so we can minimize the flow between friend-1 to friend-2 by direct pay to friend-1 to friend-3