sorting

问题 This question already has answers here : How does Javascript's sort() work? (7 answers) How does sort function work in JavaScript, along with compare function (5 answers) Closed 3 years ago . var arr = [5, 2, 1, -10, 8]; arr.sort(function(a, b) { console.log(a,b) return b - a; }) ; // 8, 5, 2, 1, -10 How does this callback work? What is the principle of choice a and b? Please explain this particular example from the inside. output console.log (at first, please explain this output ): 5 2 2 1 1

问题 Answering to another question, I wrote the program below to compare different search methods in a sorted array. Basically I compared two implementations of Interpolation search and one of binary search. I compared performance by counting cycles spent (with the same set of data) by the different variants. However I'm sure there is ways to optimize these functions to make them even faster. Does anyone have any ideas on how can I make this search function faster? A solution in C or C++ is

问题 There is a list: a = [("ax", 1), ("ec", 3), ("bk", 5)] another list: b = ["ec", "ax", "bk"] I want to sort a according to b : sort_it(a, b) a = [("ec", 3), ("ax", 1), ("bk", 5)] How to do this? 回答1: a.sort(key=lambda x: b.index(x[0])) This sorts a in-place using the the index in b of the first element of each tuple from a as the values it sorts on. Another, possibly cleaner, way of writing it would be: a.sort(key=lambda (x,y): b.index(x)) If you had large numbers of items, it might be more

问题 I want to extend a dategridview with a (read only) column just for row number. The ROW NUMBER row`s order should not change when datagridview sort by other column content (Like excel)! is possible? 回答1: We can enumerate each row in one of two ways: Adding a new column. Within the row header. Displaying in Added Column private void AddIndexCol() { DataGridViewTextBoxColumn col = new DataGridViewTextBoxColumn(); col.Name = "Index"; col.HeaderText = "Index"; col.ReadOnly = true; col.AutoSizeMode

问题 I have a question about firebase sorting. I have the next database: { "-Ka8xxTgyFB8yYKH50j_addclose" : { "number" : 0, "point" : 949739, "timestamp" : 14824078463440, "username" : "Test 16062" }, "-Ka8xzKecpbPr46Kx9gl" : { "number" : 0, "point" : 1480851, "timestamp" : 14842078463441, "username" : "Test 13599" } } I want to display data sorted by point. But i need rows only which created today. If i filter the rows for timestamp: return databaseReference .child("list") .orderByChild(

问题 I have DataGridView and I set DataSource of datagridview by using DataTables. DataTable dt = new DataTable(); dt.Columns.Add("Image",typeof(Bitmap)); dt.Columns.Add("Col2", typeof(string)); dt.Columns.Add("Col3", typeof(string)); dt.Columns.Add("Col4", typeof(string)); dt.Columns.Add("Col5", typeof(string)); int currentrow = 0; foreach (Dev d in Devs) { dt.Rows.Add(dt.NewRow()); Bitmap bmp = Test(d); dt.Rows[currentrow][0] = bmp; dt.Rows[currentrow][1] = d .ID; dt.Rows[currentrow][2] = d

问题 I have three columns - TheDate - Obviously a date. TheID - A strictly increasing ID. TheType - A Record type. I want these to sort by TheID in almost all cases except for just one record type. Records of the special record type must appear at the end of all records with the same date. Example: I want the record type 101 to appear after all other records that have the same date. In all other cases TheID controls the order. My attempt goes like: ORDER BY TheDate, CASE WHEN TheType = 101 THEN 1

问题 I have three columns - TheDate - Obviously a date. TheID - A strictly increasing ID. TheType - A Record type. I want these to sort by TheID in almost all cases except for just one record type. Records of the special record type must appear at the end of all records with the same date. Example: I want the record type 101 to appear after all other records that have the same date. In all other cases TheID controls the order. My attempt goes like: ORDER BY TheDate, CASE WHEN TheType = 101 THEN 1

问题 I have an auto-filtered range of data. The auto filter was created by the following VB code: Sub Colour_filter() Range("A4").Select Range(Selection, Selection.End(xlToRight)).Select Range(Selection, Selection.End(xlDown)).Select Selection.Copy Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks:=False, Transpose:=False Selection.AutoFilter End Sub I would like to sort the values in column "A" (the data actually start from cell "A4") by the following colour ( Color = RGB

问题 I have an auto-filtered range of data. The auto filter was created by the following VB code: Sub Colour_filter() Range("A4").Select Range(Selection, Selection.End(xlToRight)).Select Range(Selection, Selection.End(xlDown)).Select Selection.Copy Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlNone, SkipBlanks:=False, Transpose:=False Selection.AutoFilter End Sub I would like to sort the values in column "A" (the data actually start from cell "A4") by the following colour ( Color = RGB