biginteger

Does emacs have support for big numbers that don't fit in integers? If it does, how do I use them? Török Gábor Emacs Lispers frustrated by Emacs’s lack of bignum handling: calc.el provides very good bignum capabilities.— EmacsWiki calc.el is part of the GNU Emacs distribution. See its source code for available functions. You can immediately start playing with it by typing M-x quick-calc . You may also want to check bigint.el package , that is a non-standard, lightweight implementation for handling bignums. 来源： https://stackoverflow.com/questions/1371638/bignum-in-emacs-elisp

In Java, most of the primitive types are signed (one bit is used to represent the +/-), and therefore when I exceed the limits of the type, I can get unexpected results, like negative numbers. Is there any better solution than using BigInteger for this, since BigInteger has performance issues and you need to use the class methods for basic arithmetic instead of the language operators (ruins readability)? No, there is not a better solution. If you are working with values that cannot fit into a long or a double then you will need to use a reference type like BigInteger , and Java does not

The API docs says All of the details in the Spec concerning overflow are ignored, as BigIntegers are made as large as necessary to accommodate the results of an operation. Does this implies BigInteger will never overflow assuming you have sufficient memory available ? If so why do we let some "type" overflow and some don't ? As the language evolves, will it favor the types which hide overflowing mechanism from the programmers ? BigInteger will never overflow assuming you have enough memory to handle it. To answer your question of why we let some types overflow and not others: BigInteger is not

I am trying to do Factorial with Recursion and BigIntegers but eclipse is complaining about the BigInteger. I know the program is supposed to be simple but it is giving me headache. Here is the code. import java.util.Scanner; import java.math.BigInteger; public class Factorial { public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.println("Enter integer"); BigInteger n = input.nextBigInteger(); System.out.println("Factorial of " + n + " is " + fact(n)); } public static int fact(BigInteger n) { if(n ==0) { return 1; } else { return n * fact(n-1); } } }

Examples (asterisks next to odd behavior): [Fact] public void BigInteger_ToString_behavior_is_odd() { writeHex(new BigInteger(short.MaxValue)); // 7fff writeHex(new BigInteger(short.MaxValue) + 1); // 08000 ** writeHex(new BigInteger(ushort.MaxValue)); // 0ffff ** writeHex(new BigInteger(ushort.MaxValue) + 1); // 10000 writeHex(new BigInteger(int.MaxValue)); // 7fffffff writeHex(new BigInteger(int.MaxValue) + 1); // 080000000 ** writeHex(new BigInteger(uint.MaxValue)); // 0ffffffff ** writeHex(new BigInteger(uint.MaxValue) + 1); // 100000000 writeHex(new BigInteger(long.MaxValue)); //

I am trying to create an endless game such as Tap Titans, Clicker Heroes, etc. I have a BigInteger class that is capable of representing arbitrarily large integers as long as they fit into memory. Now I have a class that formats a BigInteger into a specific format. It uses K (thousand), M (million), B (billion), T (trillion), Q (quadrillion) for the 'smaller' numbers, but after that the short hand notations become ambiguous and unintuitive. Q is already ambiguous due to Quintillion, but I can live with that. After Q, I want to start from the letter a. So 1000Q = 1.000a, then 1000a = 1.000b etc

I'm looking for a way to convert a BigInteger into a very short String (shortest possible). The conversion needs to be reversible. The security of the conversion is not a big deal in this case. Would anyone have recommendations or samples of how they would go about solving this problem? One easy way is to use BigInteger.toString(Character.MAX_RADIX) . To reverse, use the following constructor: BigInteger(String val, int radix) . You can use a Base64 encoding. Note that this example uses Apache commons-codec: BigInteger number = new BigInteger("4143222334431546643677890898767548679452"); System