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C++ unordered_map using a custom class type as the key
I am trying to use a custom class as key for an unordered_map , like the following:
3 Answers
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How do I measure execution time of a command on the Windows command line?
... and later are not supported) you can use The Windows Server 2003 Resource Kit, which contains timeit.exe that displays detailed execution stats. Here is an example, timing the command "timeit -?":
C:\>timeit timeit -?
Invalid switch -?
Usage: TIMEIT [-f filename] [-a] [-c] [-i] [-d] [-s] [-t] [...
Randomize a List
...eneric list in C#? I've got a finite set of 75 numbers in a list I would like to assign a random order to, in order to draw them for a lottery type application.
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Finding quaternion representing the rotation from one vector to another
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Generate random numbers with a given (numerical) distribution
...istribution object to generate random numbers.
As pointed out by Eugene Pakhomov in the comments, you can also pass a p keyword parameter to numpy.random.choice(), e.g.
numpy.random.choice(numpy.arange(1, 7), p=[0.1, 0.05, 0.05, 0.2, 0.4, 0.2])
If you are using Python 3.6 or above, you can use r...
Efficient way to determine number of digits in an integer
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Well, the most efficient way, presuming you know the size of the integer, would be a lookup. Should be faster than the much shorter logarithm based approach. If you don't care about counting the '-', remove the + 1.
// generic solution
template <class T>
int n...
Memoization in Haskell?
Any pointers on how to solve efficiently the following function in Haskell, for large numbers (n > 108)
8 Answers
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What is the best way to get all the divisors of a number?
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Given your factorGenerator function, here is a divisorGen that should work:
def divisorGen(n):
factors = list(factorGenerator(n))
nfactors = len(factors)
f = [0] * nfactors
while True:
yield reduce(lambda x, y: x*y, [factors[x][0]**f[x] for x in range(nfactors)], 1)
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How to break out or exit a method in Java?
The keyword break in Java can be used for breaking out of a loop or switch statement. Is there anything which can be used to break from a method?
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Java Garbage Collection Log messages
.... For example, here is output from a large server application:
[GC 325407K->83000K(776768K), 0.2300771 secs]
[GC 325816K->83372K(776768K), 0.2454258 secs]
[Full GC 267628K->83769K(776768K), 1.8479984 secs]
Here we see two minor collections followed by one major collection. The numbe...