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Why is XOR the default way to combine hashes?
...om (1-bit) inputs, the AND function output probability distribution is 75% 0 and 25% 1. Conversely, OR is 25% 0 and 75% 1.
The XOR function is 50% 0 and 50% 1, therefore it is good for combining uniform probability distributions.
This can be seen by writing out truth tables:
a | b | a AND b
---+...
How to initialize a two-dimensional array in Python?
... \
for i in range (0, 10): \
new = [] \ can be replaced } this too
for j in range (0, 10): } with a list /
new.append(foo) / comprehension /
twod...
What are the mathematical/computational principles behind this game?
...
150
Finite Projective Geometries
The axioms of projective (plane) geometry are slightly different ...
How do I set a background-color for the width of text, not the width of the entire element, using CS
... I want is for the green background to be just behind the text, not to be 100% of the page width. Here is my current code:
...
What are the differences between json and simplejson Python modules?
...
wim
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answered Apr 3 '09 at 6:59
Devin JeanpierreDe...
What is the colon operator in Ruby?
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250
:foo is a symbol named "foo". Symbols have the distinct feature that any two symbols named the s...
How do you rotate a two dimensional array?
...ay you have a 4x4 two dimensional array, write a function that rotates it 90 degrees. Raymond links to a solution in pseudo code, but I'd like to see some real world stuff.
...
What is the most efficient string concatenation method in python?
... |
edited May 11 '16 at 7:04
Quentin Pradet
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answ...
Black transparent overlay on image hover with only CSS?
... the img element itself, see.
.image {
position: relative;
width: 400px;
height: 400px;
}
Give the child img element a width of 100% of the parent and add vertical-align:top to fix the default baseline alignment issues.
.image img {
width: 100%;
vertical-align: top;
}
As for th...
Regular expression for floating point numbers
...
TL;DR
Use [.] instead of \. and [0-9] instead of \d to avoid escaping issues in some languages (like Java).
Thanks to the nameless one for originally recognizing this.
One relatively simple pattern for matching a floating point number is
[+-]?([0-9]*[.])...