Need to write a specific R function - I am new to programming languages - Involving integers and vectors

Question

The question is:

Write a function sum_mult(n,v) which takes as inputs a positive integer n and a vector of positive integers v. The output should be the sum of every number less than or equal to n, which is a multiple of at least one of the entries of v.

I am given

sum_mult(10, c(3,5)) gives [1] 33

as the result.

I started originally by writing

Integer = function(n){
   n_value = sum(0:n)
   Return(n_value)
}

I don’t know if this is taking me down the wrong path, however. Any help and guidance would be appreciated

question from:https://stackoverflow.com/questions/65852466/need-to-write-a-specific-r-function-i-am-new-to-programming-languages-involv

Answer 1

Maybe you can try the code below

sum_mult <- function(n, v) sum(seq(n)[rowSums(sapply(v, function(x) seq(n) %% x) == 0) > 0])

such that

> sum_mult(5, c(2, 3))
[1] 9

> sum_mult(10, c(3, 5))
[1] 33

> sum_mult(100, c(3, 4, 5))
[1] 3046

---

Update if you want to count common multiples once or multiple times

sum_mult <- function(n, v) sum(sapply(v, function(x) sum(seq(n)[seq(n) %% x==0])))

Such that

> sum_mult(5, c(2, 3))
[1] 9

> sum_mult(10, c(3, 5))
[1] 33

> sum_mult(100, c(3, 4, 5))
[1] 4033