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How to implement a tree data-structure in Java? [closed]
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Here:
public class Tree<T> {
private Node<T> root;
public Tree(T rootData) {
root = new Node<T>();
root.data = rootData;
root.children = new ArrayList<Node<T>>();
}
public static class Node<T> {
priva...
MAMP Pro 3.05 on Mavericks updated to Yosemite - Apache does not start
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Apache started, but MySQL will not.
– Justin Putney
Feb 12 '15 at 0:38
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show 3 more ...
Facebook database design?
... has 100 friends, that means the table would contain 100'000'000'000 rows. MySQL partitioning?
– veidelis
Jun 4 '14 at 7:30
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Non-recursive depth first search algorithm
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DFS:
list nodes_to_visit = {root};
while( nodes_to_visit isn't empty ) {
currentnode = nodes_to_visit.take_first();
nodes_to_visit.prepend( currentnode.children );
//do something
}
BFS:
list nodes_to_visit = {root};
while( nodes_to_visit isn't ...
My Git repository is in the wrong root directory. Can I move it? (../ instead of ./)
...or so ago I ran the command in the directory one directory higher than the root of my project.
9 Answers
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os.walk without digging into directories below
... os.path.isdir(some_dir)
num_sep = some_dir.count(os.path.sep)
for root, dirs, files in os.walk(some_dir):
yield root, dirs, files
num_sep_this = root.count(os.path.sep)
if num_sep + level <= num_sep_this:
del dirs[:]
It works just like os.walk, but y...
IN vs OR in the SQL WHERE Clause
...')
WHERE foo = 'a' OR foo = 'b' OR foo = 'c'
According to the manual for MySQL if the values are constant IN sorts the list and then uses a binary search. I would imagine that OR evaluates them one by one in no particular order. So IN is faster in some circumstances.
The best way to know is to p...
How do I list all cron jobs for all users?
...
You would have to run this as root, but:
for user in $(cut -f1 -d: /etc/passwd); do crontab -u $user -l; done
will loop over each user name listing out their crontab. The crontabs are owned by the respective users so you won't be able to see another u...
Sass combining parent using ampersand (&) with type selectors
...his has been possible since Sass 3.3.0.rc.1 (Maptastic Maple).
The @at-root directive causes one or more rules to be emitted at the root of the document, rather than being nested beneath their parent selectors.
We can combine the @at-root directive along with interpolation #{} to arrive at the...
List files by last edited date
...ort | cut -f 2- -d ' '
The result looks a lot like ls -l:
-rw-r--r-- 1 root root 3892 08/11/2009 11:03:36 /usr/share/man/man1/xmllint.1.gz
-rw-r--r-- 1 root root 22946 08/13/2009 11:59:20 /usr/share/man/man1/curl.1.gz
-rw-r--r-- 1 root root 728 08/17/2009 12:0...