|
If you write a matching routine for file/path names, you should at least as an option treat the path separators differently. For a general matching routine, the (set of) separator character(s) should be a parameter, so the same routine can be used in different contexts, e.g. different file systems.
I guess that writing a match for ** that doesn't use recursion would require more effort and the code would be more difficult to comprehend than to do it recursively. I wouldn't ever consider flattening that recursive matching routine I use in my code. (But of course, like in all recursion, I take care to reduce the stack frame to a minimum.)
|
|
|
|
|
The original post does not mention file system anywhere.
I was thinking more in terms of a pure programming exercise.
For traversing directory structures, I use a Visitor pattern with methods of beginDir/endDir/foundFile.
This allows easy reuse of the recursive algorithm across a dozen utilities that process file trees.
Keeps the stack lean for the recursion, any bloat ends up in the Visitor’s heap memory. (Including a few utilities that needed their own stack data structure to perform their job)
|
|
|
|
|
Here edges is a String array representing a set of space separated integer pair elements e.g. "e1 e2" where 0 < e1!=e2 <= n
n is an integer, let's say ranging 0 < n <= 100000
public int sumSqrtCeil(int n, String[] edges){
...
List<Set<Integer>> edgeSetList = "converted first edges element to set of Integer"
for(int i=1;i<edges.length;i++){
Set<Integer> nodeDuo = "converted this edges element to set of Integer"
boolean found = false;
for(Integer e : nodeDuo){
for (Set<Integer> edgeSet : edgeSetList) {
found = edgeSet.contains(e);
if (found) {
break;
}
}
if(found) break;
}
if(!found){
indexOfEdgeSetList++;
edgeSetList.add(nodeDuo);
}
else{
edgeSetList.get(indexOfEdgeSetList).addAll(nodeDuo);
}
}
Set<Integer> linkedNodes =
for(int i=1;i<=n;i++){
if(!linkedNodes.contains(i)) output+=1;
}
output += edgeSetList.stream().mapToInt(integers -> (int) Math.ceil(Math.sqrt(integers.size()))).sum();
return output;
}
As per my understanding (updated) complexity should be-
O( O(A) * O(B) * O(C) + O(D) + O(E) )
O( O(edges.length) * O(2) * O(n/2) + O(n) + O(edges.length) )
O( O(edges.length) * O(n) + O(n) + O(edges.length) ) //constant removed
O( O(n*edges.length) + O(n) + O(edges.length) ) //evaluate
O( O(n^3) + O(n) + O(n^2) ) //evaluate
O( O(n^3) ) //taking biggest factor
O(n^3) - Final Time Complexity.
where,
O(edges.length) = O( n! / 2! * (n-2)! ) = O( ( n * (n-1)) / 2 ) = O( n^2 - n / 2) ==> O(n^2)
Please feel free to share also consider me a complete noob for Algorithm. Just started learning formally.
modified 24-Nov-21 1:01am.
|
|
|
|
|
You might have a better chance of getting a response if you stated the algorithm in the more general style of most textbooks rather than in C#, which not all readers understand.
|
|
|
|
|
Thanks for advise.
I am not a computer science grad, Let me have a look at an Algo book to study to update my question.
Perhaps I may not need this forum to answer this question in the process.
|
|
|
|
|
Tried to update and make simpler to understand
|
|
|
|
|
Micronaut here (Microverse Student)
To get the complexity of this algorithm is actually quite simple, just check if there is an existing nested for loops and if those for loops actually depend on the input.
For example:
for(... input.length) {
for(...input2.length) {
}
}
this code's complexity will be the length of input1 * length of input2. and if they are the same, it will be the length^2. which is what we note by n².
|
|
|
|
|
Is there any fast algorithm for this:
K people sit at a table. Each person holds a number (hi) which means: some of his neighbour has a cap of height (hi). I want to count the number of combinations for setting people up at the table according to their height of their cups.
Example:
in:
6
2 6 4 5 3 5
out:
2
(We have two combinations which are 1 2 6 4 5 3 and 6 2 1 4 5 3)
Explanation:
We know that first person points on the second person and last person points on the penultimate person. The neighbour of the second person on the left is two, so his neighbour with height 4 should be on the right. Next we know that left neighbour of fifth person is 4, so his neighbour with height 3 should be on the right. We have two combinations to place 1, 6 cups (1,6 and 6, 1):
Visualisation:
2 6 4 5 3 5
X 2 X X 5 X
X 2 X 4 5 3
Possibilities: 1 2 6 4 5 3 or 6 2 1 4 5 3
Any suggestions or help would be greatly appreciated.
|
|
|
|
|
You need to specify the problem more clearly. Does everyone at the table have two neighbors, or do the two people at each end only have one neighbour? This may or may not affect the answer.
|
|
|
|
|
How do I select a column in access database imported in window form aplication, convert it to a array and then sort it using bubble sort?
|
|
|
|
|
Firstly this is the Algorithms forum, C# is further down. Secondly your question is far too generalised for a definitive answer. You can extract data from ACCESS by the use of SQL commands. How you process the result will depend on what data that is.
|
|
|
|
|
what is the Function of algorithm it self?
|
|
|
|
|
|
Hi,
I am new here. I hope I am doing this right. If not, please advise.
I signed up to handle a neighborhood project that involves distributing about 700 items to anyone in the neighborhood who wants them. I have created an Access database containing the items with details such as the size, weight, and condition (very good to poor). I also have a Google Sheet that I populated from the database. It has one row for each item. There are columns for each of the properties (description, size, weight, condition etc.). These are all read only (protected).
The first column is the selection column. In it, the neighbor can indicate whether they want that item or not. My current thinking is to let them enter a priority number (1-10) or leave it blank.
I will allow each neighbor to access a copy of that sheet and fill in their choices. When they are all done, I will lock the sheets and import the priority columns to Excel where I am more comfortable. I have the code roughed out that will do the actual allocations.
My remaining task is to devise an algorithm for allocating items that are selected by multiple people. I could just select randomly, but I'd like an algorithm that does the allocation as fairly as possible.
I realize that "fairly" is subjective.
I currently have about 20 people who have said they want some of the items. At least one person said they would take them all.
The algorithm will start by allocating all of the items that are selected by just one person.
My current thinking for the items selected by multiple people is to calculate some measure of the percentage of the items they requested that they have already been given. Suppose A & B both choose item 143, A has 20% of their requests, and B has 30% of theirs. I could then award that item to A or, since B has 3/2 as much of their selections as does A, I could generate a random number from 1-5 and award it to A if it's 1-3, and B if 4-5. Or I could skew it more in favor of A, the one with the lower percentage.
I'm not entirely happy with this algorithm for a couple of reasons. (1) It doesn't take into account the priority choice. What if A choose the item with a priority of 5, but B chose with with a priority of 1? (2) I'm not sure of it takes into account how many items each one chose. If B only chose 1 item but A chose 100, should that one go to B, because if not, they get nothing?
I would appreciate any suggestions for good ways to handle this.
Thanks
|
|
|
|
|
You do a draw for each item.
Assign each interested party a sequential number.
Generate a random number in the above range and assign the prize.
Most other methods will be called into question.
It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food
|
|
|
|
|
Let me see if I understand what you are suggesting. I have 15-20 "takers". I give each of then a number from 1-20, right so far? Then I pick the items one at a time and draw one of the taker numbers from a hat, like a Bingo wheel. Whichever number comes up, that person gets the item. Right?
So I have almost 700 items. Are you seriously suggesting that I have 700 "draws"? If I could manage to keep each draw to 30 seconds, which I doubt, that would take almost 6 hours.
Then there is the problem that most of the takers will only want a few items. So I'd have to go through the numbers after each draw and only put in the ones who want that item. Now we are well over minute for each draw and well over 12 hours for the whole disaster.
Plus I don't want to try and find a time when all 20 takers are available.
I have the items in a database and I have a Google Sheet containing the list of items that I can share with each taker. At their leisure, they can browse the list of items and indicate which they want. I will merge those choices into an Excel sheet that will execute my allocation algorithm.
All I need is the algorithm. The key feature is breaking ties.
I am working on a way to calculate the percentage of the choices each taker has received. If 2 or more takers want the same item, I will either award it to the3 one with the lowest percentage or generate a weighted random number based on those percentages.
|
|
|
|
|
I "seriously" thought you were saying you could program.
The "draw" is simply iterating through the list of items (a "for" loop); and then executing a "RAND" function if there are takers.
The "logistics" of "having takers available" has nothing to do with the "drawing program" and any "list" you may produce saying who got what.
It would take less than a second for 700 items.
You said:
1) You "have the items in a database". Don't you know how to read them? (Part 1)
2) They "indicate their choices" which you "merge, blah blah" (Part 2)
3) Rnd Function - Access
Your (output) list could even have a "second choice" if the winner did not show up to claim their prize. Yes, they claim them; you don't chase them down or wait for them after you "publish" the list of winners. You do intend to create a winner's list? Or is this word of mouth?
Oh ... and you don't "give" them a number; you "assign" it as you "merge them" (or whatever). You need a name, you assign a number that you can later randomly generate. I suggest 1,2,3,4, ... # of takers for "that" item.
If you knew anything about "indexes" (relative or otherwise), you wouldn't even need to assign a "physical" number; it would be based on "position"; assuming an unordered list.
Note, nowhere is there any extra "draw" time.
It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food
modified 26-Aug-21 10:53am.
|
|
|
|
|
Wow! My programming skills may not be the best, but it's clear that you meet every geek stereotype, namely, social skills: non-existent.
|
|
|
|
|
What an interesting challenge !
Creating an "algorithm" for what I'd call "distributive social justice" requires you precisely define the logic of "who gets what." Of course, that logic can include introducing randomness.
Among the scenarios I'd want the algorithm to deal with:
0) "need" ... if you have a way to evaluate how much the person really needs the items, how "essential" the item is. Age ? Living alone vs, with others ? Income ? Health and access to health-care ?
1) "utility" ... if you have a way to evaluate how much the person can benefit from the items.
2) "greediness vs, modesty" ... does someone who wants everything with maximum intensity deserve more than those with fewer choices ?
3) "collateral benefits:" ... to what extent the items benefit the family, or community, of the receiver.
4) "reciprocity:" ... if you have a way to evaluate how much the person will contribute to your project.
And ... more, and more.
Given "human nature," whatever principles you define will probably anger some people ... unless you make the allocation "purely" random.
«The mind is not a vessel to be filled but a fire to be kindled» Plutarch
modified 29-Aug-21 0:20am.
|
|
|
|
|
I am a new and upcoming programmer. I want to know how can i advance my learning in data structures and algorithms.
|
|
|
|
|
Pick a language and learn about "collections".
Collections (C#) | Microsoft Docs
It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food
|
|
|
|
|
You should start with DFS, as it's very straightforward if you are familiar with recursion. BFS is slightly harder to digest for a beginner, as you'd need to understand the concept of queues first.
|
|
|
|
|
|
Hi All! I am new here.
I am wondering what is the name for the following algorithm I need to code. If I know the name I could find the algorithm.
1st example
Suppose I have a matrix
123
Aoo
Boo
C oo
D o
E oo Having it as an input I need to create an output like this:
ABx12, CEx23, Dx3 (x means cartesian product)
2nd example
12345
A oo o
B o o
Coo
Doo oo
Eo oo
F ooo should give me an output like
ABx25, CDx12, DEFx45, AFx3, Ex1
May you help me, please?
Thanks in advance,
Jacek
|
|
|
|
|
You need to guess a word. You are provided with a list of Words with the number of character matches at the right position.
Example
input {{"MOXTE",3} , {"AXCDG",0},{"MOQRT",2},{"FOUSE",4},{"POWER",1}}
return "MOUSE"
Explanation:
MOXTE MO##E 3 matches
AXCDG ##### 0 matches
MOQRT MO### 2 matches
FOUSE #OUSE 4 matches
POWER #O### 1 match
Result: MOUSE
I tried using brute force. Max heap is not working. Any leads?
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
