r/difference-of-squares: 1st iteration

r/README.md

@@ -16,3 +16,4 @@
 - [raindrops](./raindrops/README.md)
 - [leap](./leap/README.md)
 - [reverse-string](./reverse-string/README.md)
+- [difference-of-squares](./difference-of-squares/README.md)

r/difference-of-squares/README.md

@@ -34,4 +34,9 @@ Finding the best algorithm for the problem is a key skill in software engineerin
 
 ### Based on
 
-Problem 6 at Project Euler - https://projecteuler.net/problem=6
+Problem 6 at Project Euler - https://projecteuler.net/problem=6
+
+### My Solution
+
+- [difference-of-squares.R](./difference-of-squares.R)
+- [run-tests](./run-tests-r.txt)

r/difference-of-squares/difference-of-squares.R

@@ -1,5 +1,17 @@
 # this is a stub function that takes a natural_number
 # and should return the difference-of-squares as described
 # in the README.md
-difference_of_squares <- function(natural_number) {
+square_of_sum <- function(number) {
+  sum <-  number * (number + 1) / 2
+  square <- sum ^ 2
+
+  return(square)
+}
+
+sum_of_squares <- function(number) {
+  return(number * (number + 1) * (2 * number + 1) / 6)
+}
+
+difference_of_squares <- function(number) {
+  return(square_of_sum(number) - sum_of_squares(number))
 }

r/difference-of-squares/run-tests-r.txt

@@ -0,0 +1,65 @@
+Running automated test file(s):
+
+
+===============================================================================
+
+Running: ../../.github/citools/r/r-test
+
+Running R Tests
+
+R versions:
+
+	R version 4.3.3 (2024-02-29) -- "Angel Food Cake"
+	Copyright (C) 2024 The R Foundation for Statistical Computing
+	Platform: x86_64-pc-linux-gnu (64-bit)
+
+	R is free software and comes with ABSOLUTELY NO WARRANTY.
+	You are welcome to redistribute it under the terms of the
+	GNU General Public License versions 2 or 3.
+	For more information about these matters see
+	https://www.gnu.org/licenses/.
+
+
+	Rscript (R) version 4.3.3 (2024-02-29)
+
+
+ ==============================================================================
+
+Running: Rscript test_difference-of-squares.R
+
+Test passed 😀
+Test passed 😸
+Test passed 😸
+Test passed 🥇
+
+real	0m0.581s
+user	0m0.527s
+sys	0m0.055s
+
+
+ ==============================================================================
+
+Exit code: 0
+
+real	0m0.766s
+user	0m0.609s
+sys	0m0.167s
+
+real	0m0.769s
+user	0m0.611s
+sys	0m0.169s
+
+===============================================================================
+
+Running: misspell ./difference-of-squares.R ./test_difference-of-squares.R
+
+real	0m0.018s
+user	0m0.019s
+sys	0m0.009s
+
+===============================================================================
+
+/home/vpayno/git_vpayno/exercism-workspace/r
+
+===============================================================================
+