Question

给出一个包含重复项的整数数组，返回一个数组，其中所有对索引的总和为零。

[1, 2, 3, -1, 5, -5, 7, 9, -7, 2, -2] -> [ [ 3, 0 ], [ 5, 4 ], [ 8, 6 ], [ 10, 1 ], [ 10, 9 ] ]

我的JS解决方案：

function pairs(values, i) {
  if (values) {
    values.push(i);
    return values;
  }
  return [i];
}

function twoSum(arr) {
  const results = [];
  const map = new Map();
  arr.forEach((ele, i) => {
    if (map.get(-ele)) {
      map.get(-ele).forEach((e) => results.push([i, e]));
    }
    map.set(ele, pairs(map.get(ele), i));
  });
  return results;
}

来自Ruby，这是我的Ruby解决方案：

def two_sum(arr)
  hash = Hash.new { |h, k| h[k] = [] }
  arr.each.with_index.each_with_object([]) do |(ele, i), results|
    if hash.key?(-ele)
      hash[-ele].each { |e| results << [i, e] }
    end
    hash[ele] << i
  end
end

这个想法是每个哈希图键都有一个数组，对于数组中的每个元素，我们检查哈希图是否具有-element键，如果是，则将当前索引对和每个值对推入结果数组

如何使JS解决方案更加惯用？我在JS默认库（与Ruby相比）中找不到以下内容：

将可枚举对象简化为另一个可枚举对象（each_with_object）。
初始化地图，使每个新键都对应一个对象（Hash.new（[]），Hash.new（0）等）。

稍微重构了选定的解决方案，并得出以下结论：

function twoSum(arr) {
  const hash = new Map();
  return arr.reduce((results, ele, i) => {
    if (hash.has(-ele)) hash.get(-ele).forEach((e) => results.push([i, e]));
    hash.get(ele) ? hash.get(ele).push(i) : hash.set(ele, [i]);
    return results;
  }, []);
}

Answer 1

也许是这样的

function Get-GroupMembers {
    $prompt = "Enter A Group Name. Press Q to quit"
    # create an endless loop
    while ($true) {
        Clear-Host
        $answer = Read-Host $prompt
        # if the user has had enough, exit the function
        if ($answer -eq 'Q') { return }

        # try and find one or more AD groups using the answer as (part of) the name
        $group = Get-ADGroup -Filter "Name -like '*$answer*'"
        # if we have found something, exit the while loop and start enumerating the members
        if ($group) { break }

        $prompt = "Group '$answer' was not found, try again. Press Q to quit"
    }

    # you only get here if Get-ADGroup found one or more groups
    $group | ForEach-Object {
        # output a PSObject with the properties you are after
        $members = $_ | Get-ADGroupMember
        foreach ($member in $members) {
            [PsCustomObject]@{
                'Group'  = $_.DistinguishedName
                'Member' = $member.DistinguishedName
            }
        }
    }
}

# call the function
$groupinfo = Get-GroupMembers
# test if the function returned anything. 
# the user could have cancelled of the group had no members to output
if ($groupinfo) {
    Write-Host "Adding $($groupinfo.Count) items to the CSV file"
    # without -Append, you would overwrite your CSV file..
    $groupinfo | Export-Csv .\GroupMembers.csv -NoTypeInformation -Append
}
else {
    Write-Host 'Nothing found..'
}

重复的两次和问题-更惯用的Javascript解决方案

2 个答案: