169. 多数元素

/**
 * @param {number[]} nums
 * @return {number}
 */
var majorityElement = function (nums) {
  if (nums.length === 1) {
    return nums[0]
  }
  let max = 0,
    result = '',
    map = new Map(),
    i = 0
  while (max <= Math.floor(nums.length / 2)) {
    if (map.has(nums[i])) {
      const count = map.get(nums[i]) + 1
      if (max < count) {
        max = count
        result = nums[i]
      }
      map.set(nums[i], count)
    } else {
      map.set(nums[i], 1)
    }
    i++
  }
  return result
}