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How can building a heap be O(n) time complexity?
...?
Often, answers to these questions focus on the difference between siftUp and siftDown. Making the correct choice between siftUp and siftDown is critical to get O(n) performance for buildHeap, but does nothing to help one understand the difference between buildHeap and heapSort in general. Indeed, ...
Fast Bitmap Blur For Android SDK
Currently in an Android application that I'm developing I'm looping through the pixels of an image to blur it. This takes about 30 seconds on a 640x480 image.
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How to output only captured groups with sed?
...as well as specifying what you do want.
string='This is a sample 123 text and some 987 numbers'
echo "$string" | sed -rn 's/[^[:digit:]]*([[:digit:]]+)[^[:digit:]]+([[:digit:]]+)[^[:digit:]]*/\1 \2/p'
This says:
don't default to printing each line (-n)
exclude zero or more non-digits
include on...
How to get whole and decimal part of a number?
Given, say, 1.25 - how do I get "1" and ."25" parts of this number?
16 Answers
16
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Is there a standard naming convention for git tags? [closed]
... code. Using this system allows automated tools to inspect your
package and determine SemVer compliance and released versions.
When tagging releases in a version control system, the tag for a version MUST be
"vX.Y.Z" e.g. "v3.1.0".
However, after discussion this was removed, and i...
How to remove convexity defects in a Sudoku square?
...ving a Sudoku from an input image using OpenCV (as in Google goggles etc). And I have completed the task, but at the end I found a little problem for which I came here.
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How to implement a queue using two stacks?
Suppose we have two stacks and no other temporary variable.
20 Answers
20
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Why does ~True result in -2?
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int(True) is 1.
1 is:
00000001
and ~1 is:
11111110
Which is -2 in Two's complement1
1 Flip all the bits, add 1 to the resulting number and interpret the result as a binary representation of the magnitude and add a negative sign (since the number begins...
Split (explode) pandas dataframe string entry to separate rows
I have a pandas dataframe in which one column of text strings contains comma-separated values. I want to split each CSV field and create a new row per entry (assume that CSV are clean and need only be split on ','). For example, a should become b :
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How do I find the duplicates in a list and create another list with them?
How can I find the duplicates in a Python list and create another list of the duplicates? The list only contains integers.
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