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by: Markus Dehmann |
last post by:
I have a class "Data" and I store Data pointers in an STL set. But I have
millions of inserts and many more lookups, and my profiler found that they
cost a lot of runtime.
Therefore, I want to substitute the set<Data*> with a hash_set<Data*>:
typedef hash_set<const Data*, hash<const Data*>, eqData> DataPointerHashSet;
// typedef set<Data*> DataPointerHashSet; // (see complete code below)
But it doesn't work! Everything is fine...
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by: VK |
last post by:
Or why I just did myArray = "Computers" but myArray.length is
showing 0. What a hey?
There is a new trend to treat arrays and hashes as they were some
variations of the same thing. But they are not at all.
If you are doing *array", then you have to use only integer values for
array index, as it was since ALGOL.
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by: VK |
last post by:
A while ago I proposed to update info in the group FAQ section, but I
dropped the discussion using the approach "No matter what color the cat
is as long as it still hounts the mice". Over the last month I had
enough of extra proof that the cat doesn't hount mice anymore in more
and more situations. And the surrent sicretisme among array and hash is
the base for it.
I summarized all points in this article:...
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by: Sean C. |
last post by:
Helpful folks,
Most of my previous experience with DB2 was on s390 mainframe systems
and the optimizer on this platform always seemed very predictable and
consistent. Since moving to a WinNT/UDB 7.2 environment, the choices
the optimizer makes often seem flaky. But this last example really
floored me. I was hoping someone could explain why I get worse
response time when the optimizer uses two indexes, than when it uses
one. Some context:
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by: wxs |
last post by:
Many times we have a bunch of enums we have from either different enums or
the same enum that will have various numeric values assigned. Rarely will
there be collisions in numbering between the enums. These enums you might
imagine would be like OrderPrice=27, OrderQuantity=50, OrderSide=62. There
may be a lot of these. So normally what we would have to do is store these
in hash table so hashtable=value could be set with the value....
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by: bb |
last post by:
I have a requirement to create and store in our database the users
password in a couple of additional hashes (we currently store an MD5
hash)
the spec is pretty brief...
Spec:
Store the NT Hash and Unix Crypt of password when a user
creates/modifies password
End.
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by: Diane |
last post by:
Hi everybody. Does anyone have any sample hash table implementation for
separate chaining? I'm trying to implement it myself, but I'm stuck.
Thanks!
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by: Johan Tibell |
last post by:
I would be grateful if someone had a minute or two to review my hash
table implementation. It's not yet commented but hopefully it's short
and idiomatic enough to be readable. Some of the code (i.e. the
get_hash function) is borrowed from various snippets I found on the
net. Thee free function could probably need some love. I have been
thinking about having a second linked list of all entries so that the
cost of freeing is in proportion to...
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by: ravi |
last post by:
Hi
can anybody tell me that which ds will be best suited to implement a
hash table in C/C++
thanx. in advanced
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by: Oralloy |
last post by:
Hello folks,
I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>".
The problem is that using the GNU compilers, it seems that the internal comparison operator "<=>" tries to promote arguments from unsigned to signed.
This is as boiled down as I can make it.
Here is my compilation command:
g++-12 -std=c++20 -Wnarrowing bit_field.cpp
Here is the code in...
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by: jinu1996 |
last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven tapestry of website design and digital marketing. It's not merely about having a website; it's about crafting an immersive digital experience that captivates audiences and drives business growth.
The Art of Business Website Design
Your website is...
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by: tracyyun |
last post by:
Dear forum friends,
With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each protocol has its own unique characteristics and advantages, but as a user who is planning to build a smart home system, I am a bit confused by the choice of these technologies. I'm particularly interested in Zigbee because I've heard it does some...
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by: isladogs |
last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM).
In this session, we are pleased to welcome a new presenter, Adolph Dupré who will be discussing some powerful techniques for using class modules.
He will explain when you may want to use classes instead of User Defined Types (UDT). For example, to manage the data in unbound forms.
Adolph will...
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by: conductexam |
last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and then checking html paragraph one by one.
At the time of converting from word file to html my equations which are in the word document file was convert into image.
Globals.ThisAddIn.Application.ActiveDocument.Select();...
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by: TSSRALBI |
last post by:
Hello
I'm a network technician in training and I need your help.
I am currently learning how to create and manage the different types of VPNs and I have a question about LAN-to-LAN VPNs.
The last exercise I practiced was to create a LAN-to-LAN VPN between two Pfsense firewalls, by using IPSEC protocols.
I succeeded, with both firewalls in the same network. But I'm wondering if it's possible to do the same thing, with 2 Pfsense firewalls...
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by: adsilva |
last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?
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by: 6302768590 |
last post by:
Hai team
i want code for transfer the data from one system to another through IP address by using C# our system has to for every 5mins then we have to update the data what the data is updated we have to send another system
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by: muto222 |
last post by:
How can i add a mobile payment intergratation into php mysql website.
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