tracks/r/exercises/perfect-numbers/example.R in trackler-2.1.0.48 vs tracks/r/exercises/perfect-numbers/example.R in trackler-2.1.0.49

@@ -1,7 +1,15 @@
 is_perfect <- function(n){
   
+  # catch invalid input
+  if (n <= 0)
+    stop("Classification is only possible for natural numbers.")
+  
+  # catch edge cases
+  if (n %in% c(1, 2))
+    return("deficient")
+  
   find_factors <- function(n) {
     factors <- c()
     for (i in 2:floor(n^0.5 + 1)) {
       
       if (n %% i == 0) {
@@ -15,8 +23,16 @@
             
     }
     unique(factors)
   }
   
-  sum(find_factors(n)) + 1 == n
+  sum <- sum(find_factors(n)) + 1
   
+  if (sum == n)
+    return("perfect")
+  else-if (sum > n)
+    return("abundant")
+  else-if (sum < n)
+    return("deficient")
+  
+  # alternative to multiple if/else-if predicates: dplyr::case_when()
 }