sorting

问题 A stable sort is a sort that maintains the relative ordering of elements with the same value. The docs on ArrayList.Sort say that when an IComparer is provided the sort is stable: If comparer is set to null, this method performs a comparison sort (also called an unstable sort); that is, if two elements are equal, their order might not be preserved. In contrast, a stable sort preserves the order of elements that are equal. To perform a stable sort, you must implement a custom IComparer

问题 Im working on a nodejs+mongodb project using mongoose. Now I have come across a question I don't know the answer to. I am using aggregation framework to get grouped results. The grouping is done on a date excluding time data field like: "2013 02 06". Code looks like this: MyModel.aggregate([ {$match: {$and: [{created_date: {$gte: start_date}}, {created_date: {$lte: end_date}}]}}, {$group: { _id: { year: {$year: "$created_at"}, month: {$month: "$created_at"}, day: {$dayOfMonth: "$created_at"}

问题 This question already has answers here : how to keep elements of a list based on another list (3 answers) Closed 7 months ago . I have two list, one reference and one input list Ref = [3, 2, 1, 12, 11, 10, 9, 8, 7, 6, 5, 4] Input = [9, 5, 2, 3, 10, 4, 11, 8] I want to sort Input list, in the order as that of Ref. If some element is missing in Input list, it can skip and go for the other element. Hence sorted Input list, based on Ref list will be like this Sorted_Input = [3, 2, 11, 10, 9, 8, 5

问题 I have a array of objects for use in D3 e.g var cities = [ { city: "London", country: "United Kingdom", index: 280 }, { city: "Geneva", country: "Switzerland", index: 259 }, { city: "New York City", country: "United States", index: 237 }, { city: "Singapore", country: "Singapore", index: 228 }, { city: "Paris", country: "France", index: 219 }, { city: "San Francisco", country: "United States", index: 218 }, { city: "Copenhagen", country: "Denmark", index: 217 }, { city: "Sydney", country:

问题 I am creating a list of dicts, then I want to sort the dicts in the list by the value of the key, lowest to highest. Everything works except the sort: def pythagorean(x1, y1, x2=0, y2=0): return ((x1 - x2)**2 + (y1 - y2)**2)**0.5 points = [(-2, -4), (0, -2), (-1, 0), (3, -5), (-2, -3), (3, 2)] dicts = [] for coord in points: d = {} a1, b1 = coord distance = pythagorean(a1, b1) d[distance] = (a1, b1) dicts.append(d) for i in dicts: print(i) dist_list = [] for item in dicts: for key in item:

问题 I have a class PropertyDetails : public class PropertyDetails { public int Sequence { get; set; } public int Length { get; set; } public string Type { get; set; } } I am creating a list of PropertyDetails as List<PropertyDetails> propertyDetailsList=new List<PropertyDetails>(); I want to sort this list by PropertyDetails.Sequence . Linq solutions are welcome. 回答1: If you want to sort the existing list in-place then you can use the Sort method: List<PropertyDetails> propertyDetailsList = ...

问题 I'm writing a library routine, which among other things will do some rather complex sorting of nested arrays. I see from the documentation that all the array sort function (including the ones using built-in comparators) can return false on failure - but when would this ever be the case??? 回答1: It would fail when the variable you send to the function is NOT an array Example: asort('Hello');//fails asort(array(1,2,35,7,2,8,3));//true 回答2: I also stumbled upon this question and did some research

问题 I'm writing a library routine, which among other things will do some rather complex sorting of nested arrays. I see from the documentation that all the array sort function (including the ones using built-in comparators) can return false on failure - but when would this ever be the case??? 回答1: It would fail when the variable you send to the function is NOT an array Example: asort('Hello');//fails asort(array(1,2,35,7,2,8,3));//true 回答2: I also stumbled upon this question and did some research

问题 I am trying to order the products by sku within an order in an email in Woocommerce . I have not had any luck with the following code. Some help? Thanks since now! add_filter( 'woocommerce_order_get_items', function( $items, $order ) { uasort( $items, function( $a, $b ) { return strnatcmp( $a['_sku'], $b['_sku'] ); } ); return $items; }, 10, 2 ); Sample sort result: INFSTRAW I NFMUFFIN INFFLORES INFTAFLOR INFTAPINK CTEPINK4 CTECAKE4 INFCHOCO UCUBTOMA 回答1: Updated On July 2020 Here is the way

问题 I am trying to order the products by sku within an order in an email in Woocommerce . I have not had any luck with the following code. Some help? Thanks since now! add_filter( 'woocommerce_order_get_items', function( $items, $order ) { uasort( $items, function( $a, $b ) { return strnatcmp( $a['_sku'], $b['_sku'] ); } ); return $items; }, 10, 2 ); Sample sort result: INFSTRAW I NFMUFFIN INFFLORES INFTAFLOR INFTAPINK CTEPINK4 CTECAKE4 INFCHOCO UCUBTOMA 回答1: Updated On July 2020 Here is the way