219. 存在重复元素 II

/**
 * @param {number[]} nums
 * @param {number} k
 * @return {boolean}
 */
var containsNearbyDuplicate = function (nums, k) {
  const map = new Map()
  for (let i = 0; i < nums.length; i++) {
    if (map.has(nums[i])) {
      const indexs = map.get(nums[i])
      for (let j = 0; j < indexs.length; j++) {
        if (Math.abs(indexs[j] - i) <= k) {
          return true
        }
      }
      indexs.push(i)
      map.set(nums[i], indexs)
    } else {
      map.set(nums[i], [i])
    }
  }
  return false
}