In this post, we will solve Ruby Partial Applications HackerRank Solution. This problem (Ruby Partial Applications) is a part of HackerRank Ruby series.
Problem
In Partial Application, we create a lambda that takes a parameter and returns a lambda that does something with it.
Example:
multiply_function = -> (number) do
-> (another_number) do
number * another_number
end
end
doubler = multiply_function.(2)
tripler = multiply_function.(3)
puts doubler.(4)
puts tripler.(4)
In the above example, the lambda will take number as a parameter, and return a lambda. When you call this lambda with another_number, it will return the product of the two.
Task
You are given a partially complete code. Your task is to fill in the blanks (_______
).
Here, combination is a variable that stores a partial application which computes combination nCr.
Solution – Ruby Partial Applications – HackerRank Solution
combination = -> (n) do -> (r) do # https://en.wikipedia.org/wiki/Combination (n-r+1..n).inject(:*) / (1..r).inject(:*) end end n = gets.to_i r = gets.to_i nCr = combination.(n) puts nCr.(r)
Note: This problem (Ruby Partial Applications) is generated by HackerRank but the solution is provided by CodingBroz. This tutorial is only for Educational and Learning purpose.