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Fast permutation -> number -> permutation mapping algorithms

...lation w[k-1] = k! is easily proved by induction.) The number we get from converting our sequence will then be the sum of s[k] * w[k], with k running from 0 to n-1. Here s[k] is the k'th (rightmost, starting at 0) element of the sequence. As an example, take our {1, 2, 0, 1, 0}, with the rightmost ...
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how to convert from int to char*?

... Also, you need 12 characters to convert a 32-bit integer to a nul-terminated base-10 representation. 10 isn't enough for -2147483647. – Steve Jessop Jun 1 '12 at 9:12 ...
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How to check if a Constraint exists in Sql server?

...rent_object_id) AS TableName ,type_desc AS ConstraintType FROM sys.objects WHERE type_desc LIKE '%CONSTRAINT' AND OBJECT_NAME(OBJECT_ID)='XYZ' If you need even more constraint information, look inside the system stored procedure master.sys.sp_helpconstraint to see how to ge...
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Converting int to bytes in Python 3

...s much more expensive, so never use lists when you can use tuples. You can convert bigger integers by using int.to_bytes(3, "little"). Initializing bytes with a given length makes sense and is the most useful, as they are often used to create some type of buffer for which you need some memory of gi...
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Assign pandas dataframe column dtypes

... pd.to_timedelta and pd.to_numeric (As mentioned below, no more "magic", convert_objects has been deprecated in 0.17) df = pd.DataFrame({'x': {0: 'a', 1: 'b'}, 'y': {0: '1', 1: '2'}, 'z': {0: '2018-05-01', 1: '2018-05-02'}}) df.dtypes x object y object z object dtype: object df x ...
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How to convert a boolean array to an int array

I use Scilab, and want to convert an array of booleans into an array of integers: 6 Answers ...
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How can I convert bigint (UNIX timestamp) to datetime in SQL Server?

How can I convert UNIX timestamp (bigint) to DateTime in SQL Server? 15 Answers 15 ...
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Formatting Numbers by padding with leading zeros in SQL Server

...)) + EmployeeId If the column is an INT, you can use RTRIM to implicitly convert it to a VARCHAR SELECT REPLICATE('0',6-LEN(RTRIM(EmployeeId))) + RTRIM(EmployeeId) And the code to remove these 0s and get back the 'real' number: SELECT RIGHT(EmployeeId,(LEN(EmployeeId) - PATINDEX('%[^0]%',Empl...
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Converting Stream to String and back…what are we missing?

...s to a formatted string a formatted string to the original bytes look at Convert.ToBase64String and Convert. FromBase64String share | improve this answer | follow ...
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What's the strangest corner case you've seen in C# or .NET? [closed]

... the amount of points given to customers. The issue was related to casting/converting double to int. In code below: double d = 13.6; int i1 = Convert.ToInt32(d); int i2 = (int)d; does i1 == i2 ? It turns out that i1 != i2. Because of different rounding policies in Convert and cast operator the...