array-intersect

问题 I've written a short function for array intersection and wanted to know why one function is faster than the other. 1) Dim list2() As String 'Assume it has values' Dim list2length As Integer = list2.length Function newintersect(ByRef list1() As String) As String() Dim intersection As New ArrayList If (list1.Length < list2length) Then 'use list2' For Each thing As String In list2 If (Array.IndexOf(list1, thing) <> -1) Then intersection.Add(thing) End If Next Else 'use list1' For Each thing As

问题 I'm trying to make advanced search filters in an application that holds resources (people). I've got all the results in 1 multidimensional array. A user of the application can search for the persons Job title, skills, work field and country. I've already made the part where I look up the people that meet the criteria given by the user. These results are stored in a multidimensional array. If the user is looking for someone with a specific resource with a job title and a specific skill the

问题 What, and how much, is faster - manually iterating over an array with foreach and checking for needle occurrence with in_array() , or using array_intersect() ? 回答1: Benchmark Test Script <?php $numbers = range(32, 127); $numbersLetters = array_map('chr', $numbers); for (;;) { $numbersLetters = array_merge($numbersLetters, $numbersLetters); if (count($numbersLetters) > 10000) { break; } } $numbers = range(1, count($numbersLetters)); printf("Sample size: %d elements in 2 arrays (%d total) \n",

问题 I need to count the number of elements corresponding to the intersection of two big arrays of strings and do it very fast. I am using the following code: arr1[i].Intersect(arr2[j]).Count() For CPU Time, VS Profiler indicates 85.1% in System.Linq.Enumerable.Count() 0.3% in System.Linq.Enumerable.Intersect() Unfortunately it might to take hours to do all work. How to do it faster? 回答1: You can use HashSet with arr2 HashSet<string> arr2Set = new HashSet<string>(arr2); arr1.Where(x=>arr2Set

问题 Is there any function similar to "array_intersect" but it is in mode case-insensitive and ignoring tildes? The array_intersect PHP function compares array elements with === so I do not get the expected result. For example, I want this code : $array1 = array("a" => "gréen", "red", "blue"); $array2 = array("b" => "green", "yellow", "red"); $result = array_intersect($array1, $array2); print_r($result); Outputs gréen and red . In default array_intersect function just red is proposed (normal cause

问题 I am trying to find the intersection values between multiple arrays. for example code1 = [1,2,3] code2 = [2,3,4] code3 = [0,2,6] So the result would be 2 I know in PHP you can do this with array_intersect I wanted to be able to easily add additional array so I don't really want to use multiple loops Any ideas ? Thanks, Alex 回答1: Use the & method of Array which is for set intersection. For example: > [1,2,3] & [2,3,4] & [0,2,6] => [2] 回答2: If you want a simpler way to do this with an array of

问题 I am trying to find the intersection values between multiple arrays. for example code1 = [1,2,3] code2 = [2,3,4] code3 = [0,2,6] So the result would be 2 I know in PHP you can do this with array_intersect I wanted to be able to easily add additional array so I don't really want to use multiple loops Any ideas ? Thanks, Alex 回答1: Use the & method of Array which is for set intersection. For example: > [1,2,3] & [2,3,4] & [0,2,6] => [2] 回答2: If you want a simpler way to do this with an array of

问题 I have two arrays: $arr1 = array(101 => 250, 102 => 250, 103 => 250, 104 => 500, 105 => 500, 106 => 500,); and $arr2 = array(0 => 103, 1 => 104, 2 => 105) The result I want to get is Array (103 => 250, 104 => 500) I have tried working with array_intersect(array_flip($arr1), $arr2); but array_flip($arr1) gives something like Array(103 => 250, 106 => 500) thus, keys get lost and can not be intersected correctly. Is there a way to get the desired result? 回答1: The following code does the job. I

问题 I have the following two arrays: $array_one = array('colorZero'=>'black', 'colorOne'=>'red', 'colorTwo'=>'green', 'colorThree'=>'blue', 'colorFour'=>'purple', 'colorFive'=>'golden'); $array_two = array('colorOne', 'colorTwo', 'colorThree'); I want an array from $array_one which only contains the key-value pairs whose keys are members of $array_two (either by making a new array or removing the rest of the elements from $array_one ) How can I do that? I looked into array_diff and array

问题 I have array values in single array and I need to intersect the arrays inside the main array. Here is my code: $a[1] = array ( 'value' => 'America','value1' => 'England1','value2' => 'Australia','value3' => 'England','value4' => 'Canada', ); $a[2] = array ( 'value' => 'America','value1' => 'Wales','value2' => 'Australia','value3' => 'England1','value4' => 'Canada', ); $a[3] = array ( 'value' => 'America','value1' => 'England','value2' => 'Australia','value3' => 'England1','value4' => 'Canada'