删除排序数组中的重复项 ​

function removeDuplicates(nums) {
  let i = 0

  for (; i < nums.length; i++) {
    if (nums[i] === nums[i + 1]) {
      nums.splice(1, i)
      i--
    }
  }

  return i
}

function removeDuplicates(nums) {
  let child = 0, father = 0

  for (; father<nums.length; father++) {
    if (nums[child] !== nums[father]) {
      child++
      nums[child] = nums[father]
    }
  }

  return child + 1
}