recursion

问题 I am part of a small team working on a fairly small website with user accounts; there are about 100 users at this time. And we are using Amazon Cognito for user management. On our website there is a summary page which displays a list/table of all users and various attributes. However, there's a hard limit on the number of items returned by the Amazon Cognito listUsers API call, in this case 60. Luckily, the API call also returns a token to use to make subsequent calls if there are more users.

问题 I have a need to recursively descend a linked list database tree item 1-> item 2 -> item 3 -> item 4 -> item 5 -> item 6 -> item 7 -> item 8 my pseudo code is var getItems = function(itemid) { db.getitem(itemid, function(item) { item.items.forEach(function(subitem) { getItems(subitem.id) }) }) getItems(1) however, db.getItem is an asynchronous function I would like to return a JS object in the same structure as the diagram to the top-level caller what is the best way of achieving this ? I don

问题 I have written a method pythagoreanTriplets in scala using nested loops. As a newbie in scala, I am struggling with how can we do the same thing using recursion and use Lazy Evaluation for the returning list(List of tuples). Any help will be highly appreciated. P.S: The following method is working perfectly fine. // This method returns the list of all pythagorean triples whose components are // at most a given limit. Formula a^2 + b^2 = c^2 def pythagoreanTriplets(limit: Int): List[(Int, Int,

问题 I have written a method pythagoreanTriplets in scala using nested loops. As a newbie in scala, I am struggling with how can we do the same thing using recursion and use Lazy Evaluation for the returning list(List of tuples). Any help will be highly appreciated. P.S: The following method is working perfectly fine. // This method returns the list of all pythagorean triples whose components are // at most a given limit. Formula a^2 + b^2 = c^2 def pythagoreanTriplets(limit: Int): List[(Int, Int,

问题 When I run this piece of code for n=5 the output I get is "5 3 1 1 3 5" I get the 5 3 1 part but after that n=-1 but when I run the code with a debugger it when n=-1 it goes to the line after numbers(n-2); i.e System.out.prt(n+ ""); even though that statement is contained in the if block. Why does this happen? public void numbers(int n) { if(n>0) { System.out.print(n+" "); numbers(n-2); System.out.print(n+" "); } } TLDR : when n=-1 System.out.prt(n+ ""); even though it is within the if block

问题 I'm in trouble creating a combination of elements from list. What i would like to do is to create a recursive function in Python which returns a combination of elements for example list a = [1,2,3,4,5,6,7,8] and a result will be combinations [1,2,3,4],[1,3,4,5],[1,4,5,6],[1,2,4,5] etc. For 8 elements it should return 70 combinations (if i did my math right). Although the best option would be that the combinations don't repeat. I tried to code it, but what i get is only [1,2,3,4],[1,3,4,5] etc

问题 I'm trying to render a component recursively. On each recursive call I subtract 10 px from the dimensions. I expect a series of nested divs, each one 10px smaller. When the height and width reach 10px, the component should return null, so that is my base case. Instead of expected result, I've got nothing. No errors in the terminal, no errors in the dev tools, just a page that is frozen. Any thoughts? RecurentDiv.js : const RecurentDiv = ({ width, height }) => { const style = { width: `${width

问题 I'm trying to wrap my head around how recursion works, particularly how you can break it down into sub parts and work on that while maintaining that it all belongs to one overall part, if that makes any sense. So for example: if I am given a list like [1,2,3,4,5] and I want to write a function that continuously creates a dictionary within a dictionary with each element in the list being the key; the output being like this - {1:{2:{3:{4:{5:{}}}}}}. I know it can be done with a simple for loop

问题 The intent for the JSON data below is to update the value of the field dst with the value of src within all elements of type t , regardless of depth within the tree, while at the same time preserving the whole structure of the data. Is this possible with jq ? My several attempts have boiled down to the following command that is not working to achieve the intended purpose: $ jq -r 'map_values(select(.. | .type? == "t" |= (.dst = .src)))' { "a": "b", "c": [ { "type": "t", "src": "xx", "dst":

问题 I want to know the depth of an element in a list in Python using a recursive loop (not a function) but it doesn't work. I find some answers with functions but it's not the point here. Something like 'a' is depth 2 and 'd' is depth 3 in the list below Here is my code: list1 = [['x','y'], ['z','p'], ['m',['a','b','c',['d','e']]]] level = 0 def print_list(l): for e in l: global level if type(e) == list: print_list(e) level +=1 else: print(str(e) + ",", str(level)) print_list(list1) Result: x, 0