HackerRank içerisinde bulunan “Viral Advertising” sorusunun açıklaması ve çözümü. HackerLand Enterprise firması yeni bir reklam stratejisi üzerinde çalışıyor. İlk günde bu reklamı 5 kişiye gösteriyorlar sosyal medyada. Ve bu kişi sayısının yarısı 3’er arkadaşı ile paylaşıyor bu reklamı. Size verilen n gün sonra bu reklamı kaç kişi gördüğünü bulmanız isteniyor.

► HackerRank – Viral Advertising: https://www.hackerrank.com/challenges/strange-advertising/problem

► Problem açıklaması:

HackerLand Enterprise is adopting a new viral advertising strategy. When they launch a new product, they advertise it to exactly 5 people on social media.

On the first day, half of those 5 people (i.e., 5 / 2 = 2) like the advertisement and each shares it with 3 of their friends. At the beginning of the second day, (5 / 2 * 3 = 2 *3 = 6) people receive the advertisement.

Each day, floor(recipients / 2) of the recipients like the advertisement and will share it with 3 friends on the following day. Assuming nobody receives the advertisement twice, determine how many people have liked the ad by the end of a given day, beginning with launch day as day 1.

Example

n = 5.

Day Shared Liked Cumulative

1 5 2 2

2 6 3 5

3 9 4 9

4 12 6 15

5 18 9 24

The progression is shown above. The cumulative number of likes on the 5th day is 24.

Function Description

Complete the viralAdvertising function in the editor below.

viralAdvertising has the following parameter(s):

int n: the day number to report

Returns

int: the cumulative likes at that day

Input Format

A single integer, , the day number.

Constraints

Sample Input

3

Sample Output

9