set

问题 While I solve an algorithm question, My solution couldn't get passed because of time issue. But I realized that the only difference between passed one and mine was bag.lower_bound(jewerly[i].first) != bag.end() //passed lower_bound(bag.begin(), bag.end(), jewerly[i].first) != bag.end() //failed I've already checked it with clock() and It was obviously slower than the other one. what makes the difference between the two codes? #include <cstdio> #include <set> #include <algorithm> using

问题 In collection we could sort the set or map as per to our requirement. Treeset or TreeMap also provides the sorted collection. Is there any benefit of using treeset when we require sorted collection 回答1: The posters before be have not mentioned an important criterion: If the elements in your collection change their state often after insertion, i.e. you need to re-sort the same collection several times, maybe a TreeSet or TreeMap are not ideal because elements are only sorted during insertion,

问题 I have a set M which consists of three subsets A,B and C. Problem: I would like to calculate all possible subsets S(1)...S(N) of M which contain all possible pairs between elements of A, B and C in such manner that: elements of A and B can happen in a pair only once for each of two positions in a pair (that is {a1,a2} and {b1,a1} can be in one subset S, but no more elements {a1,_} and {_,a1} are allowed in this subset S); elements of C can happen 1-N times in a subset S (that is {a,c}, {b,c},

问题 I have a text input correctly set in html. When this method is called pressing a button: this._searchInput.setAttribute("value", "pippo"+Math.random()); console.log(this._searchInput.value); It works correctly, and input text fields shows the string with random number. Alas, if I type once inside the input text field, all subsequent calls to set value are ignored. Method is called since console outputs the same value visible in text field. Any suggestion? Is there a reson why after typing in

问题 I have a question regarding the .pop() method. In the documentation, it states that on sets: Remove and return an arbitrary element from the set. So what exactly does "arbitrary" mean? Like, for example: If I wanted to build a queue from a list of users where position is determined at random, could I enter in all users into a set, and then build a randomly assigned queue using .pop()? So the code would look something like queue_set = {'bob','rachel','sara','david'} queue = dequeue([]) while

问题 Say that I have the two following one row datasets: data have_1; input message $ order_num time price qty; datalines; A 3 34199 10 500 run; data have_2; input message $ order_num time delete_qty ; datalines; B 2 34200 100 run; I have another dataset that aggregates previous order_numbers. data total; input order_num time price qty; datalines; 1 34197 11 550 2 34198 10.5 450 run; My objective is that I need to update the dataset total with the dataset have_1 and have_2 in a loop. When I start

问题 I'm trying a long time to remove duplicate from a list and create a dictionary with keys like php (0,1,2....). I have tried : ids = dict(set([1,2,2,2,3,4,5,4,5,6])) print ids Then I want to for key, value in ids.iteritems(): #stuff Of course I get the following error because ids is not a dictionary: TypeError: cannot convert dictionary update sequence element #0 to a sequence Thanks! Edit: I think my data was a bit misleading: I have a list: [foo, bar, foobar, barfoo, foo, foo, bar] and I

问题 Beginner here, I'm a bit lost with es6 set , map and generators. How can I select an item in a map, then iterate backwards from that point on effectively? Preferably without going through the whole set/map. let v = myMap.get('key') so, from 'v' to the beginning of the map (backwards)? thank you! 回答1: You can create a set of iteration helpers and then compound to create the effect you want: /* iterTo iterates the iterable from the start and up to (inclusive) key is found. The function

问题 I have this Windows batch file and I cannot get to work it properly. Basically I have a folder in one location and I need to copy it to another folder, but to also have the new folder name renamed. @Echo off :: set 836147398 = @Taunus_A3 :: Echo Copying %836147398% xcopy "C:\Users\arrona\Desktop\Update Mods\steamapps\workshop\content\107410\836147398" "C:\TCAFiles\Games\arma3exile\TCA.Mods\%836147398%" /s/h/e/k/f/c So what I need is that the folder contents of 333310405 are copied to C:

问题 I've got a set of pointers which I would like to iterate over in a deterministic manner. Obviously if I use the default sort order for set, this will be based on the pointers memory addresses which can be different each time the program runs. So I define a custom comparator which I want to use, but I don't want to change the templated type of the set (because it's used in a million places in the code), so I want to pass in a comparator object to the set constructor which is derived from std: