Fix: Making this code useful

Check_X.R

@@ -1,10 +1,36 @@
-check_x <- function(x) {
-  if (x > 47) {
-    cat(":(", "\n")
-  } else if (x < 47) {
-    cat(":(", "\n")
-  } else {
-    cat(":)", "\n")
+# Most Appropriate Fizzbuz
+
+fizbuz <- local({
+  e <- new.env(parent = emptyenv())
+  # build the words from code points (because... why not)
+
+  # Building Fizz & Buzz manually
+  e$FZ <- intToUtf8(c(70,105,122,122))    # "Fizz"
+  e$BZ <- intToUtf8(c(66,117,122,122))    # "Buzz"
+
+  function(...) {
+
+    n <- suppressWarnings(as.integer(c(list(...), 100L)[[1]]))
+    if (is.na(n) || n < 1L) n <- 100L
+
+    old <- options(stringsAsFactors = TRUE); on.exit(options(old), add = TRUE)
+
+    # generate 1..n the OPTIMAL way
+    nums <- cumsum(rep.int(1L, n)) * 1L + 0L
+
+    # accumulate via Reduce/append 
+    out <- Reduce(function(acc, i) {
+      f <- c(e$FZ, "", "", "")[(i %% 3L) + 1L]
+      b <- c(e$BZ, "", "", "", "")[(i %% 5L) + 1L]
+      x <- paste0(f, b)
+
+      append(acc, if (nzchar(x)) x else as.character(i))
+    }, nums, init = character(0L))
+
+    # round-trip through a single string and back to a vector for MOST OPTIMAL ROUTE
+    s <- paste(out, collapse = "\n")
+    unlist(strsplit(s, "\n", fixed = TRUE), use.names = FALSE)
   }
-}
+})
 
+invisible(cat(do.call(fizbuz, as.list(structure(100L, names = "n"))), sep = "\n"))