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Giant constant numbers.
Posted: 7 Aug 2017 15:26
If I am doing some odd maths how does one get large numbers into integer64 variables and constants.
There is a unsigned64:value function I think that takes two parameters.
One of my constants is 80 characters for I might have to call a 128 bit library.
In C and C++ one always added a L to the end of your number constant.
unsigned var = 7362398263876L;
I believe that C++ 11 has 128 bit numbers now.
Posted: 7 Aug 2017 19:24
I do not think there are 128 bit numbers (by default) in C++ 11, but it is not something I know for sure.
However, the 'L' in C/C++ literals indicates a 64 bit number.
I Visual Prolog you can use the types unsigned64
and you do not need to use any special marks to write such numbers:
Code: Select all
value : unsigned64 = 7362398263876.
p : (unsigned64 X) -> unsigned64 Y.
p(X) = 7362398263876 + value + X.
unsigned64 have the range [0..18446744073709551615].
integer64 have the range [-9223372036854775808..9223372036854775807].
128 bit numbers cannot hold a 80 digit number, the largest number in an 128 bit unsigned is 2^128 ~ 3,4e38 (i.e. 39 digits).
A real can hold very large numbers, but (only) with ~15 digits precision.
Posted: 7 Aug 2017 23:47
Hello Chris (and Thomas and all),
the below attached project gives an example how one could deal with numbers which exceed the limits of the build-in number domains. The example implements large unsigned integer numbers encoded in binaries. The implemented arithmetics uses however only the -simple- school methods. For multiplication and especially for division faster (but more complicated) algorithms are known.
Posted: 8 Aug 2017 5:54
Thanks gentlemen for your assistance.