Add solution #829

Author: JoshCrozier

README.md

@@ -637,6 +637,7 @@
 826|[Most Profit Assigning Work](./0826-most-profit-assigning-work.js)|Medium|
 827|[Making A Large Island](./0827-making-a-large-island.js)|Hard|
 828|[Count Unique Characters of All Substrings of a Given String](./0828-count-unique-characters-of-all-substrings-of-a-given-string.js)|Hard|
+829|[Consecutive Numbers Sum](./0829-consecutive-numbers-sum.js)|Hard|
 830|[Positions of Large Groups](./0830-positions-of-large-groups.js)|Easy|
 831|[Masking Personal Information](./0831-masking-personal-information.js)|Medium|
 841|[Keys and Rooms](./0841-keys-and-rooms.js)|Medium|

solutions/0829-consecutive-numbers-sum.js

@@ -0,0 +1,28 @@
+/**
+ * 829. Consecutive Numbers Sum
+ * https://leetcode.com/problems/consecutive-numbers-sum/
+ * Difficulty: Hard
+ *
+ * Given an integer n, return the number of ways you can write n as the sum of consecutive
+ * positive integers.
+ */
+
+/**
+ * @param {number} n
+ * @return {number}
+ */
+var consecutiveNumbersSum = function(n) {
+  let result = 0;
+
+  for (let k = 1; k < Math.sqrt(2 * n); k++) {
+    const numerator = n - (k * (k - 1)) / 2;
+    if (numerator % k === 0) {
+      const startingNum = numerator / k;
+      if (startingNum > 0) {
+        result++;
+      }
+    }
+  }
+
+  return result;
+};