Data commit

Task/Four-is-magic/R/four-is-magic.r

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+# provided by neonira
+
+integerToText <- function(value_n_1) {
+  english_words_for_numbers <- list(
+    simples = c(
+      'zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine',
+      'ten', 'eleven', 'twelve', 'thirteen', 'fourteen', 'fifteen', 'sixteen', 'seventeen', 'eighteen', 'nineteen'
+    ),
+    tens = c('twenty', 'thirty', 'forty', 'fifty', 'sixty', 'seventy', 'eighty', 'ninety'),
+    powers = c(
+      'hundred'     = 100,
+      'thousand'    = 1000,
+      'million'     = 1000000,
+      'billion'     = 1000000000,
+      'trillion'    = 1000000000000,
+      'quadrillion' = 1000000000000000,
+      'quintillion' = 1000000000000000000
+    )
+  )
+
+  buildResult <- function(x_s) {
+    if (value_n_1 < 0) return(paste('minus', x_s))
+    x_s
+  }
+  withDash <- function(a_s, b_s) paste(a_s, b_s, sep = '-')
+  val <- abs(value_n_1)
+  if (val < 20L) return(buildResult(english_words_for_numbers$simples[val + 1L]))
+  if (val < 100L) {
+    tens <- val %/% 10L - 1L
+    reminder <- val %% 10L
+    if (reminder == 0L) return(buildResult(english_words_for_numbers$ten[tens]))
+    return(buildResult(withDash(english_words_for_numbers$ten[tens], Recall(reminder))))
+  }
+
+  index <- l <- length(english_words_for_numbers$powers)
+  for(power in seq_len(l)) {
+    if (val < english_words_for_numbers$powers[power]) {
+      index <- power - 1L
+      break
+    }
+  }
+
+  f <- Recall(val %/% english_words_for_numbers$powers[index])
+  reminder <- val %% english_words_for_numbers$powers[index]
+  if (reminder == 0L) return(buildResult(paste(f, names(english_words_for_numbers$powers)[index])))
+  buildResult(paste(f, names(english_words_for_numbers$powers)[index],  Recall(reminder)))
+}
+
+magic <- function(value_n_1) {
+  text <- vector('character')
+  while(TRUE) {
+    r <- integerToText(value_n_1)
+    nc <- nchar(r)
+    complement <- ifelse(value_n_1 == 4L, "is magic", paste("is", integerToText(nc)))
+    text[length(text) + 1L] <- paste(r, complement)
+    if (value_n_1 == 4L) break
+    value_n_1 <- nc
+  }
+
+  buildSentence <- function(x_s) paste0(toupper(substr(x_s, 1L, 1L)), substring(x_s, 2L), '.')
+  buildSentence(paste(text, collapse = ', '))
+}