Software Engineer

You are given an integer array 'ARR' of size 'N' and an integer 'S'. Your task is to return the list of all pairs of elements such that each sum of elements of each pair equals 'S'.

Note:

Each pair should be sorted i.e the first value should be less than or equals to the second value. 

Return the list of pairs sorted in non-decreasing order of their first value. In case if two pairs have the same first value, the pair with a smaller second value should come first.

You are given an array of ‘N’ integers. You need to return another array ‘product’ such that ‘product[i]’ contains the product of all the arrays except the element at the ith position in the given array.

Note

As the product of elements can be very large you need to return the answer in mod (10^9+7).

Follow Up

Try to do this without using the division operator ‘/’, in constant space. The output array does not count as extra space for the purpose of space complexity analysis.

The Ultimate Ninja Ankush was bored, so his friend Ninja Nikhil decided to give him a puzzle to keep him entertained. Nikil gave Ankush ‘N’ integers and asked how many groups of sizes 2 and 3 can be formed such that the sum of the group is divisible by 3. Although the Ultimate Ninja Ankush is brilliant, some extra help is always appreciated. Can you help The ultimate ninja Ankush with this so that he can prove to Nikhil that he, in fact, is the ultimate ninja?

More formally, Given an array of size ‘N’, we can form a group of two or three. The group should be such that the sum of all elements in that group is a multiple of 3. Count all possible numbers of groups that can be generated in this way.

For example

Given:
‘N’ = 5, ‘ARR’ = [1, 2, 3, 4, 5].
The answer will be two since 8 since 8 pairs can be formed and those are (1,3), (1,2), (1,5), (2,4), (4,5),(1,2,3), (3,4,5), (1,3,5). Therefore the final answer is 8.

He gave me a scenario and asked me to design a system for it , it was about 40 mins discussion.
He said , ” There are some islands initially they are not connected with each other. Now if i give a query like Build(A,B) this means that you have to make a bridge from island A to island B. First , i will give you multiple queries to build bridges then if i give you query like Bridge(A,B) then you have to tell the newest bridge among all the paths from A to B ? “.
It was a graph based problem so i explained him DFS approach for this problem , he was satisfied with my approach . Further he added some more questions in it , i explained those as well.
He asked me do you have any question for me ? In PPT they told us about one of the product opera working for ,so i asked him about the algorithm used for that product.He explained me core part of that product.