SDE - 1

You are given an array consisting of 'N' positive integers, and your task is to find the number of subsequences with odd sum and the number of subsequences with even sum. As the numbers can be too large, you need to return both the numbers mod 10 ^ 9 + 7.
A subsequence is a sequence that can be derived from the given sequence by deleting zero or more elements without changing the order of the remaining elements. For example, consider the array {1, 2, 3}, there are 7 possible subsequences for this. They are {1}, {2}, {3}, {1,2}, {1,3}, {2,3}, {1,2,3}.
Even sum subsequence means the subsequence whose total sum( sum of all the elements in the subsequence) is divisible by 2. And for odd sum subsequence, the total sum leaves a remainder of 1 when divided by 2.
Note:
1) In general, for an array of size 'N', there are (2 ^ 'N' - 1) non-empty subsequences possible. Because we are not considering empty subsequence for this problem.

2) The array may contain duplicate elements.

3) X mod 10 ^ 9 + 7 is the remainder when X is divided by 10 ^ 9 + 7.

Virtual memory is a very useful memory management technique which enables processes to execute outside of memory. This technique is especially used when an executing program cannot fit in the physical memory.

The application has mainly 3 components… 

Client: Device (User Interface) which is used to browse and play Netflix videos. TV, XBOX, laptop or mobile phone, etc
OC (Open connect) or Netflix CDN: CDN is the network of distributed servers in different geographical locations, and Open Connect is Netflix’s own custom global CDN (Content delivery network). It handles everything which involves video streaming. It is distributed in different locations and once you hit the play button the video stream from this component is displayed on your device. So if you’re trying to play the video sitting in North America, the video will be served from the nearest open connect (or server) instead of the original server (faster response from the nearest server).
Backend (Database): This part handles everything that doesn’t involve video streaming (before you hit the play button) such as onboarding new content, processing videos, distributing them to servers located in different parts of the world, and managing the network traffic. Most of the processes are taken care of by Amazon Web Services.