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Windows Registry

The Windows registry is a local database of settings used by Microsoft's Windows operating systems. Questions about the registry itself, registry problems, and software which changes the registry belong here.

368 Questions

What is the essence of heap sort?

The essence of heap sort is the heap.

A heap is a complete binary tree. That is; every parent node has two child nodes except the last parent which may have either one or two children depending on the total number of nodes. The last parent in the heap is always the rightmost parent on the lowest level. The minimum size of a heap is 2 elements.

The primary property of a heap is that every parent's value is greater-than or equal-to the values of its child or children. This means that the root node (the top of the heap) always holds the largest value in the heap.

Child nodes are denoted as left and right but the final parent need not have a right child. Where both are present, no order is specified. That is; the left child can either be less-than, equal-to or greater-than the right child. Although it is possible to specify an order (such that left is always less-than or equal to right), there is no benefit in doing so.

Heap sort requires random access and is therefore most efficiently implemented using an array. Sorting can be done in-place in logarithmic time and with minimal space overhead but, like quicksort, it is not stable (equal elements may not be in the same order they were input). While somewhat slower than quick sort, in practice it has a more favourable worst-case of O(n log n).

Heap sort can also be thought of as being an improved selection sort. Like selection sort, the input set is divided into two, with an unsorted set and a sorted set, extracting the largest value from the unsorted set and placing it in the sorted set. However, selection sort requires a linear-time search to locate the largest value, whereas heap-sort can achieve this in constant time (because the largest value is always at the top of the heap). The main overheads are in the initial construction of the heap (which takes linear time) and in repairing the heap after extracting each value (which is logarithmic). Selection sort is reasonably efficient when working with small sets (although an insertion sort is usually more efficient) while heap sort is much better for larger sets but still somewhat slower than quick sort in practice.

An array provides the most compact and efficient storage of a heap because the structure of the heap (the actual links between any child and its parent, in either direction) can be computed using trivial arithmetic. That is; given the zero-based index of any element within the heap, we can determine the indices of the parent and the left and right child as follows:

parent = floor ((index - 1) / 2)

left = 2 * index + 1

right = 2 * index + 2

[The floor function is a standard function which returns the largest integer that is not greater than its argument. That is, floor(0.9) will always return the integer 0 rather than "round up" to 1, because 1 would be greater than 0.9].

Heap sort makes use of two helper functions, one to construct the initial heap and the other to repair the heap each time we extract the largest value (the root value).

The repair algorithm is known as a "sift down" and this requires that we pass the index of the parent to be sifted as well as the index of the last value in the heap. The index of the last value is important because if we pass the index of the last parent in the current heap and that parent has no right child, the "right" equation would produce an index that is greater than the last index, so we must guard against that. Leaf nodes have no children, but the algorithm is such that we never pass the index of a leaf node, so we don't need to guard against the "left" equation producing an invalid index.

The purpose of the sift down algorithm is to examine the parent value with its child value(s) to determine which is the largest. If the parent holds the largest, the algorithm does nothing (the heap is valid for that particular parent). Otherwise, it swaps the parent value with the largest child and if the child is not a leaf, repeats the process for that child. In other words, the original parent value finds its correct place within the heap rooted by that parent.

Construction is an iterative algorithm known as "heapify" that traverses the unordered set in reverse order from the back of the array. On each iteration we locate the parent of the current index, thus we can ignore index 0 since it has no parent (it is the root). Once we have located the parent, we perform a repair (a sift-down) with that parent. Since we work from the back of the array, the heap is effectively built from the bottom up, one layer at a time, with lower values sifting down and thus forcing larger values up. The final iteration places the largest value in the root.

Thus, given an array, a, with n elements, we can implement the heap sort algorithm as follows (in pseudocode):

heapify (a, n)

end = n - 1

while end > 0 do

{

swap (a[0], a[end])

end = end - 1

sift_down (a, 0, end)

}

Given an array a with n elements, the heapify algorithm can be implemented as follows:

start = floor ((n - 2) / 2)

while start >= 0 do

{

sift_down (a, start, n - 1)

start = start - 1

}

Finally, given an array a, with a heap rooted at index start and a last value at index end, the sift_down algorithm can be implemented as follows:

root = start

while root * 2 + 1 <= end do

{

left = root * 2 + 1

swap = root

if a[swap] < a[left] then swap = left

right = left + 1

if right <= end and a[swap] < a[right] then swap = right

if swap == root then return

swap (a[root], a[swap])

root = swap

}

What is 429cad59-35b1-4dbc-bb6d-1db246563521?

Most likely you refer to {429CAD59-35B1-4DBC-BB6D-1DB246563521} which is the name of a folder/directory in Windows system folders program/application data for (legacy) program files (x86) 32 bits. Do not mess with it, many things may go wrong if you do. Remember that 64 bits os like W7 still handle many 32 bits programs like MS Office, Internet Explorer or iTunes.

You just bought another used dell computer How can you change who the computer is registered to also you have tried deleting an administrator account with no success help please?

The following information is based on you running Windows XP or Windows Vista.

Click Start, then Run and type in Regedit.exe and hit enter. A box will popup with drop down Windows, navigate to "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion" and change it from the previous owner to your name.

It is not recommended to delete the "Administrator" account. However, other user accounts can be deleted from the User Accounts menu located at Start -> Settings -> Control Panel -> User Accounts.

What is full form of SSDD?

If you mean in computer technology it's a term used to describe an older and largely unused format of Floppy disks "Single sided, double density" disks.

It could also mean "Same sh*t, different day" depending on whom you ask.

What does the National Provider Identifier Registry provide?

The National Provider Identifier Registry provides identification of every health care provider. It uses a 10 digit number that is assigned to each health provider so they can be linked to their transactions.

What does restriction for land registry mean?

In England & Wales restrictions prohibit the making of an entry in respect of a disposition or a disposition of a specified kind. The prohibition may be indefinite or for a specified period and it may be absolute or conditional on something happening (for example on the consent of a third party being obtained).

The related link explains what a restriction is, the types available and how to apply to have one registered, modified, disallowed or removed from the land register

What is the address of Barnsley Land Registry?

The Barnsley area is dealt with by the Land Registry, Nottingham Office

Full details of the Land Registry offices and the areas they serve can be obtained using the attached link

If you need to contact Land Registry then use the link Contact Us before visiting a local office

Which post you can display your talent without have problem?

My talient never explain any person but when i do the work than every person see my Talent.So i am never Explain.

Where can one learn more about a Regtool?

A "regtool" is used to view and edit the Microsoft Windows registry. General information on that Windows registry can be found for example at Wikipedia (article "Windows Registry"). There one can also find mre information on registry tools (chapter 3.1 "Registry editors").

Which among the four language modes is very important?

Listening because it is the first skill that is being developed especially when we are babies.

What is the solution of error code 80072e3?

Without knowing which program or system generated the error it is impossible to say. The error code is just a number. Many programs and systems may produce the exact same error code but its actual meaning is specific to the program or system that generated it.

What was window of the west?

It was a plain land and nobody owned it so Russia got the land.

How do you eat a window?

by chewing it from one corner to the opposite!

How do you restore back your operating system if it written on by another operating system?

Answer: Do you mean you want to restore an OS which was overwritten by another? You can't. Once all of the important files have been overwritten, there's nothing much you can do except reinstall the original operating system from scratch.

Answer: A typical hard disk can only have one partition set to be the active boot partition, even though there may be boot programs on more than one partition.

Sometimes during installation of an OS, the boot location is changed to the new partition/OS bootstrap program. This leaves the previous partition/OS bootstrap program inaccessible. This may be corrected by configuring a Dual-boot option in the new bootstrap program to reach both OS.

You may be able to alter the active boot partition to reach the original bootstrap program, and add a dual-boot option to the original bootstrap program to reach both OS. I can recommend using the free/open software gPartEd to change this boot partition and SuperGrub to modify a GNU/Linux boot program.

What is MSS.chk?

The term MSS.chk is a check file that is attached to a message file. They often contain viruses and need to be scanned before opened.

What is the activation key for Registry Reviver?

It is the license required to unlock complete functionality of the program.

You can get one on their website.