#829 - Consecutive Numbers Sum

Hard • View on LeetCode • View on GitHub

Problem Description

Given an integer n, return the number of ways you can write n as the sum of consecutive positive integers.

Solution

/**
 * @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;
};