From c5c581da5f1ed10ef46b70ddff8fd585c7ac92cd Mon Sep 17 00:00:00 2001
From: Philip Obosi <philip.obosi@eng.uniben.edu>
Date: Wed, 20 Feb 2019 17:49:48 +0100
Subject: [PATCH] added rangeSum

---
 Beginner/rangeSum/index-SOLUTION.js | 35 +++++++++++++++++++++++++++++
 Beginner/rangeSum/index-START.js    |  5 +++++
 Beginner/rangeSum/test.js           |  0
 3 files changed, 40 insertions(+)
 create mode 100644 Beginner/rangeSum/index-SOLUTION.js
 create mode 100644 Beginner/rangeSum/index-START.js
 create mode 100644 Beginner/rangeSum/test.js

diff --git a/Beginner/rangeSum/index-SOLUTION.js b/Beginner/rangeSum/index-SOLUTION.js
new file mode 100644
index 0000000..629e306
--- /dev/null
+++ b/Beginner/rangeSum/index-SOLUTION.js
@@ -0,0 +1,35 @@
+// USING A FOR LOOP
+function rangeSum(arr) {
+  let sum = 0;
+  for (i = arr[0]; i <= arr[1]; i++) {
+    sum += i;
+  }
+  return sum;
+}
+
+// USING THE ARITHMETIC PROGRESSION FORMULA
+function rangeSum(arr) {
+  let arrList = [];
+  for (i = arr[0]; i <= arr[1]; i++) {
+    arrList.push(i);
+  }
+  return (arrList.length * (arr[0] + arr[1])) / 2;
+}
+
+// USING RECURSION
+function rangeSum(arr) {
+  if (arr[0] == arr[1]) {
+    return arr[0];
+  } else {
+    return rangeSum([arr[0], arr[1] - 1]) + arr[1];
+  }
+}
+
+// USING .REDUCE()
+function rangeSum(arr) {
+  let arrList = [];
+  for (i = arr[0]; i <= arr[1]; i++) {
+    arrList.push(i);
+  }
+  return arrList.reduce((acc, num) => acc + num, 0);
+}
diff --git a/Beginner/rangeSum/index-START.js b/Beginner/rangeSum/index-START.js
new file mode 100644
index 0000000..ea938be
--- /dev/null
+++ b/Beginner/rangeSum/index-START.js
@@ -0,0 +1,5 @@
+function rangeSum(arr) {
+  // Code goes here
+}
+
+module.exports = rangeSum;
diff --git a/Beginner/rangeSum/test.js b/Beginner/rangeSum/test.js
new file mode 100644
index 0000000..e69de29