Data commit

Task/Happy-numbers/R/happy-numbers-1.r

@@ -0,0 +1,29 @@
+is.happy <- function(n)
+{
+   stopifnot(is.numeric(n) && length(n)==1)
+   getdigits <- function(n)
+   {
+      as.integer(unlist(strsplit(as.character(n), "")))
+   }
+   digits <- getdigits(n)
+   previous <- c()
+   repeat
+   {
+      sumsq <- sum(digits^2, na.rm=TRUE)
+      if(sumsq==1L)
+      {
+         happy <- TRUE
+         break
+      } else if(sumsq %in% previous)
+      {
+         happy <- FALSE
+         attr(happy, "cycle") <- previous
+         break
+      } else
+      {
+         previous <- c(previous, sumsq)
+         digits <- getdigits(sumsq)
+      }
+   }
+   happy
+}

Task/Happy-numbers/R/happy-numbers-2.r

@@ -0,0 +1 @@
+is.happy(2)

Task/Happy-numbers/R/happy-numbers-3.r

@@ -0,0 +1,2 @@
+#Find happy numbers between 1 and 50
+which(apply(rbind(1:50), 2, is.happy))

Task/Happy-numbers/R/happy-numbers-4.r

@@ -0,0 +1,9 @@
+#Find the first 8 happy numbers
+happies <- c()
+i <- 1L
+while(length(happies) < 8L)
+{
+   if(is.happy(i)) happies <- c(happies, i)
+   i <- i + 1L
+}
+happies