difference-of-squares

difference-of-squares/src/difference_of_squares.gleam

@@ -0,0 +1,16 @@
+pub fn square_of_sum(n: Int) -> Int {
+  let sum = sum_to(n)
+  sum * sum
+}
+
+fn sum_to(n: Int) -> Int {
+  n * { n + 1 } / 2
+}
+
+pub fn sum_of_squares(n: Int) -> Int {
+  n * { n + 1 } * { 2 * n + 1 } / 6
+}
+
+pub fn difference(n: Int) -> Int {
+  square_of_sum(n) - sum_of_squares(n)
+}