Step by Step solution about How to resolve the algorithm Harshad or Niven series step by step in the Julia programming language

The provided Julia code defines several functions for working with Harshad numbers, which are numbers that are divisible by the sum of their digits.

isharshad(x): This function checks if a given number x is a Harshad number by calculating the sum of its digits and checking if x is divisible by that sum. It returns true if x is a Harshad number and false otherwise.

nextharshad(x): This function finds the next Harshad number after x. It does this by incrementing x by 1 until it finds a number that is a Harshad number.

harshads(n): This function returns a vector of the first n Harshad numbers. It initializes a vector h with n elements and sets the first element to 1. Then, for each subsequent element, it uses nextharshad to find the next Harshad number after the previous element and stores it in the vector. Finally, it returns the vector h.

Usage:

The code demonstrates the usage of these functions by printing the first 20 Harshad numbers and finding the first Harshad number after 1001.

Output:

First 20 harshad numbers: 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 21, 22, 24, 26, 27, 28, 30, 32, 36
First harshad number after 1001: 1008

isharshad(x)   = x % sum(digits(x)) == 0
nextharshad(x) = begin while !isharshad(x+1) x += 1 end; return x + 1 end

function harshads(n::Integer)
	h = Vector{typeof(n)}(n)
	h[1] = 1
	for j in 2:n
		h[j] = nextharshad(h[j-1])
	end
	return h
end

println("First 20 harshad numbers: ", join(harshads(20), ", "))
println("First harshad number after 1001: ", nextharshad(1000))