set

问题 For now, at least since IntelliJ Idea 14+, ide remembers the last set of opened projects. Could we control it comfortably and have switchable sets (groups) of projects? This is another way of opening projects, not like Modules. My hope is some plugin already do the functionality, but which one? 回答1: As of 2017-08, IntelliJ Idea 2017.2.1 can group projects. To use the feature, in the project selection window, right-click on the project name: I've created a group called 'kata', that contains

问题 I was surprised to discover recently that while dicts are guaranteed to preserve insertion order in Python 3.7+, sets are not: >>> d = {'a': 1, 'b': 2, 'c': 3} >>> d {'a': 1, 'b': 2, 'c': 3} >>> d['d'] = 4 >>> d {'a': 1, 'b': 2, 'c': 3, 'd': 4} >>> s = {'a', 'b', 'c'} >>> s {'b', 'a', 'c'} >>> s.add('d') >>> s {'d', 'b', 'a', 'c'} What is the rationale for this difference? Do the same efficiency improvements that led the Python team to change the dict implementation not apply to sets as well?

问题 Say I'm making a chess app, in which a position is stored like this: struct Position { var pieces: Set<Piece> // some other stuff } Piece is defined as follows: struct Piece: Hashable { var row: Int var column: Int let player: Player let type: PieceType var hashValue: Int { return 8 * row + column } } Player and PieceType are simple enums: enum Player { case White, Black } enum PieceType { case Queen, King, ... } Now, I would like to access a Piece in a Position by its position on the board.

问题 Say I'm making a chess app, in which a position is stored like this: struct Position { var pieces: Set<Piece> // some other stuff } Piece is defined as follows: struct Piece: Hashable { var row: Int var column: Int let player: Player let type: PieceType var hashValue: Int { return 8 * row + column } } Player and PieceType are simple enums: enum Player { case White, Black } enum PieceType { case Queen, King, ... } Now, I would like to access a Piece in a Position by its position on the board.

问题 What is the best way to check whether a certain value is in a string slice? I would use a Set in other languages, but Go doesn't have one. My best try is this so far: package main import "fmt" func main() { list := []string{"a", "b", "x"} fmt.Println(isValueInList("b", list)) fmt.Println(isValueInList("z", list)) } func isValueInList(value string, list []string) bool { for _, v := range list { if v == value { return true } } return false } http://play.golang.org/p/gkwMz5j09n This solution

问题 For example, when I execute frozen = frozenset(('kay', 'snow queen')) , then tuple(frozen) , I get ('kay', 'snow queen') . (When / how) is it possible, if ever, for iter(frozen) to produce the items in a different order? (When / how) will tuple(frozen) return ('snow queen', 'kay') ? I am using Python 3 almost all of the time, but I would also be curious about Python 2. 回答1: By default, the hash values of str objects are salted with an unpredictable random value. Although they remain constant

问题 MSets appear to be the way to go for OCaml-style finite sets. Sadly, I can't find example uses. How can I define an empty MSet or a singleton MSet ? How can I union two MSets together? 回答1: Let me show a simple example for finite sets of natural numbers: From Coq Require Import MSets Arith. (* We can make a set out of an ordered type *) Module S := Make Nat_as_OT. Definition test := S.union (S.singleton 42) (S.empty). (* membership *) Compute S.mem 0 test. (* evaluates to `false` *) Compute S

问题 and thanks for help words = [....#Big list of words] words_set = set(words) I have hard time determine what is the complexity of set(words) when n=len(words). Is it O(n) since it moves on all the items of the list, or O(l(n-l)) when l is a single word length? Thanks for help! If there is a difference between WC and BC too. Edit: don't mind O(l(n-l)) it's mistake for repeating substring big O. 回答1: I don't understand your second option, but iterating a list is O(n) and you must iterate the

问题 I have a column in DataFrame containing list of categories. For example: 0 [Pizza] 1 [Mexican, Bars, Nightlife] 2 [American, New, Barbeque] 3 [Thai] 4 [Desserts, Asian, Fusion, Mexican, Hawaiian, F... 6 [Thai, Barbeque] 7 [Asian, Fusion, Korean, Mexican] 8 [Barbeque, Bars, Pubs, American, Traditional, ... 9 [Diners, Burgers, Breakfast, Brunch] 11 [Pakistani, Halal, Indian] I am attempting to do two things: 1) Get unique categories - My approach is have a empty set, iterate through series and

问题 I have a column in DataFrame containing list of categories. For example: 0 [Pizza] 1 [Mexican, Bars, Nightlife] 2 [American, New, Barbeque] 3 [Thai] 4 [Desserts, Asian, Fusion, Mexican, Hawaiian, F... 6 [Thai, Barbeque] 7 [Asian, Fusion, Korean, Mexican] 8 [Barbeque, Bars, Pubs, American, Traditional, ... 9 [Diners, Burgers, Breakfast, Brunch] 11 [Pakistani, Halal, Indian] I am attempting to do two things: 1) Get unique categories - My approach is have a empty set, iterate through series and