function twoSum(nums: number[], target: number): number[] {
  const map: Record<number, number> = {}
  const n = nums.length

  for (let l = 0, r = n - 1; l <= r; l++, r--) {
    let v = nums[l]
    let diff = target - v

    if (map[diff] !== undefined) return [map[diff], l]
    map[v] = l

    v = nums[r]
    diff = target - v

    if (map[diff] !== undefined) return [map[diff], r]
    map[v] = r
  }

  return []
}