카타 6급 Multiples of 3 or 5

R

solution <- function(number){
  if( number < 3 ) return(0)
  number = number - 1
  sum(c(0:(number %/% 3)))*3 + sum(c(0:(number %/% 5)))*5 - sum(c(0:(number %/% 15)))*15
}

solution <- function(number){
  numbers <- 1:(number - 1)
  return(sum(numbers[which(numbers %% 3 == 0 | numbers %% 5 == 0)]))
}

solution <- function(number){
  if(number < 3) { return(0) }
  else {
    to_number <- 1:(number-1)
    return(sum(to_number[to_number %% 3 == 0 | to_number %% 5 == 0]))
  }
}

solution <- function(number){
  if(number < 3) { return(0) }
  else {
    to_number <- 1:(number-1)
    return(sum(to_number[to_number %% 3 == 0 | to_number %% 5 == 0]))
  }
}

solution <- function(number){
  number = number -1
  n3 = floor(number/3)
  n5 = floor(number/5)
  n15= floor(number/15)
  return(n3*(n3+1)*1.5 + n5*(n5+1)*2.5 - n15*(n15+1)*7.5)
}