/**
 * @param {number[]} nums
 * @return {number}
 */
var findLHS = function (nums) {
  let map = {};
  for (let i of nums) {
    map[i] = (map[i] || 0) + 1;
  }
  let maxResultLength = 0;
  for (let [key, value] of Object.entries(map)) {
    if (map[key - 1]) {
      maxResultLength = Math.max(maxResultLength, map[key - 1] + value);
    }
  }
  return maxResultLength;
};