tree-traversal

问题 I have an parent child array similar to this: Array ( [0] => Array ( [category_id] => 1 [category_name] => Home & Garden [parent_id] => 0 [level] => 1 ) [1] => Array ( [category_id] => 2 [category_name] => Kitchen & Dining [parent_id] => 1 [level] => 2 ) [2] => Array ( [category_id] => 3 [category_name] => Food & Beverage Carriers [parent_id] => 2 [level] => 3 ) [3] => Array ( [category_id] => 4 [category_name] => Flasks [parent_id] => 3 [level] => 4 ) [4] => Array ( [category_id] => 5

问题 Can anyone help me out to get postorder traversal as output from gven two traversals: In-order :A, B, C, D, E, F, G, H, J, K, L, M, P, Q, N. Pre-order : C, D, E, B, G, H, F, K, L, P, Q, M, N, J, A. It will be more helpfull if the answere is graphical. 回答1: Non-Recursive Algorithm ;How to Calculate change Between inorder and preorder ؟؟ #include<stdio.h> #include<conio.h> #include <iostream> using namespace std; int find(int *p,int s,int f) { int k=0; if (f==0) return -1; for(;k<s;k++) if(*(p

问题 My first time ever trying to traverse directories, but stat is throwing errors for some of the directories due to what seems to be a lack of permission. Error: EPERM: operation not permitted, stat 'K:\System Volume Information' I'd like to simply avoid calling stat on a given directory in the first place if it is going to throw an error, yet I can't figure out how to do it. I've tried looking into ignoring protected directories altogether. However, all of the questions I came across used

问题 I'm struggling with the printing of a binary tree that I coded. It's a little program where you can type in different states and then it orders them alphabetically in the binary tree and afterwards it should print them out again, in alphabetic order. How should I start with the listing function? I read in the internet that a recursive algorithm would be the best, but I don't really know how to do that with my setup. #include <iostream> #include <stdlib.h> #include <string> using namespace std

问题 This question already has answers here : Traversing a n-ary tree without using recurrsion (3 answers) Closed last year . Intuitively I understand that I keep on stack pairs like (node, iterator) , but still I can not get to a working solution. 回答1: You can always translate a recursive algorithm to one with an explicit stack. Start with recursive code: void traverse(NODE *p) { if (p) { for (int i = 0; i < p->n_children; ++i) { traverse(p->child[i]); } } } Replace the recursive call: struct {

问题 My question is mostly algorithm-related and not specific to a specific programming language Assuming we have a graph represented by a list of lists, where each internal list represents two nodes and a numbered edge, Is is possible to implement a recursive BFS (breadth-first search) function using ONLY the following 12 functions? Our bfs recursive function is supposed to take 5 arguments: the graph to be searched the element to find the search queue list of visited nodes current element we're

问题 I want to write a function load: 'a option list -> 'a tree , that restores binary tree from the given list, which contains the elements in postfix order. If the list does not represent any tree, your function should raise the exception Load (you have to declare it earlier). The tree is defined as : type ‘a btree = L of ‘a | N of ‘a btree * ‘a btree So far what I did was : exception Load ;; let rec load l = match l with | [] -> raise Load | Some x::_ -> L x | None::t -> N(?,load t) ;; Here's

问题 using jQuery I would like to transform this: <h3>Question 1</h3> <p>Answer 1 P1</p> <p>Answer 1 P2</p> <h3>Question 2</h3> <p>Answer 2 P1</p> <p>Answer 2 P2</p> <p>Answer 2 P3</p> Into: <ul> <li> <h3>Question 1</h3> <div> <p>Answer 1 P1</p> <p>Answer 1 P2</p> </div> </li> <li> <h3>Question 2</h3> <div> <p>Answer 2 P1</p> <p>Answer 2 P2</p> <p>Answer 2 P3</p> </div> </li> </ul> Any suggestion would be really appreciated. Thank you! 回答1: I'm using nextUntil to select all p elements after each

问题 I have an HTML list ( <ul> , <li> , etc.) of pages, with multiple items at various depths. I am trying to write some code to traverse this list one element at a time. So a "next " button would return the ID of the following <li> element, which could be a direct sibling of the current element, or it would be in a child <ul> element, or it could be in a parent <ul> element. Likewise, a "prev" button would do the same, but in reverse. Here is some example html: <ul> <li id="post_item_1"><a href=

问题 I'm pretty much a beginner in programming, currently trying to build my first web scraper using JSoup. So far I am able to get the data that I want from a single page of my target site, but naturally I would like to somehow iterate over the entire site. JSoup seems to offer some kind of traversor/visitor (what's the difference?) for that, yet I have absolutely no idea how to make that work. I know what trees and nodes are and know the structure of my target site, but I don't know how to