biginteger

Is there a really large variable type I can use in Java to store huge numbers (up to around forty digits)? long 's maximum value is 9223372036854775807, which is 19 digits -- not nearly large enough. I'm trying to create a calculator that can handle large numbers, because most nowadays can only hold an insufficient 10 digits or so, and I want want accurate calculations with numbers of a much larger magnitude EDIT Thanks for the answers. I can use BigInteger for big integers, the only limit being the computer's memory (should be sufficient). For decimals, I'll use float ^e, as @WebDaldo

We know that using double for currency is error-prone and not recommended. However, I'm yet to see a realistic example, where BigDecimal works while double fails and can't be simply fixed by some rounding. Note that trivial problems double total = 0.0; for (int i = 0; i < 10; i++) total += 0.1; for (int i = 0; i < 10; i++) total -= 0.1; assertTrue(total == 0.0); don't count as they're trivially solved by rounding (in this example anything from zero to sixteen decimal places would do). Computations involving summing big values may need some intermediate rouding, but given the total currency in

I was wondering if there was any way to convert a variable of type Integer, to BigInteger. I tried typecasting the Integer variable, but i get an error that says inconvertible type. The method you want is BigInteger#valueOf(long val) . E.g., BigInteger bi = BigInteger.valueOf(myInteger.intValue()); Making a String first is unnecessary and undesired. You can do in this way: Integer i = 1; new BigInteger("" + i); 来源： https://stackoverflow.com/questions/3878192/converting-from-integer-to-biginteger

I'm currently building a project which involves a lot of collective intelligence. Every user visiting the web site gets created a unique profile and their data is later used to calculate best matches for themselves and other users. By default, Django creates an INT(11) id field to handle models primary keys. I'm concerned with this being overflown very quickly (i.e. ~2.4b devices visiting the page without prior cookie set up). How can I change it to be represented as BIGINT in MySQL and long() inside Django itself? I've found I could do the following ( http://docs.djangoproject.com/en/dev/ref

Hmm. There doesn't seem to me a way to store Python's bigintegers in a numpy array. Is there something special you have to do, to declare a numpy array with bigints? Not specifically, no. You can create an array with dtype='object' , which creates an array of Python objects (including but not limited to ints). This will get you a lot of Numpy array-like functionality but few to none of the performance benefits. Which is to say, an array of Python objects is not significantly different from a Python list in terms of memory performance. Though if you must use bigints it may still be preferable

How do hig-performance native big-integer libraries on x86-64 represent a big integer in memory? (or does it vary? Is there a most common way?) Naively I was thinking about storing them as 0-terminated strings of numbers in base 2 64 . For example suppose X is in memory as: [8 bytes] Dn . . [8 bytes] D2 [8 bytes] D1 [8 bytes] D0 [8 bytes] 0 Let B = 2 64 Then X = D n * B n + ... + D 2 * B 2 + D 1 * B 1 + D 0 The empty string (i.e. 8 bytes of zero) means zero. Is this a reasonable way? What are the pros and cons of this way? Is there a better way? How would you handle signedness? Does 2's

What is general principals to operate with large integers in javascript? Like in libraries for bigint? How i do it by myself? You may take a look at this implementation . You may also find other implementations useful. Another option I've used in the past, is to hand off those operations to a calculation server via jsonp. If you're working with such large numbers, you likely want the improved performance and precision this can give you. 来源： https://stackoverflow.com/questions/3579153/large-integers-in-javascript-more-the-253-1

How can I implement this python code in c#? Python code: print(str(int(str("e60f553e42aa44aebf1d6723b0be7541"), 16))) Result: 305802052421002911840647389720929531201 But in c# I have problems with big digits. Can you help me? I've got different results in python and c#. Where can be mistake? Primitive types (such as Int32 , Int64 ) have a finite length that it's not enough for such big number. For example: Data type Maximum positive value Int32 2,147,483,647 UInt32 4,294,967,295 Int64 9,223,372,036,854,775,808 UInt64 18,446,744,073,709,551,615 Your number 305,802,052,421,002,911,840,647,389

Could anyone help me in converting an 18 digit string numeric to BigInteger in java ie;a string "0x9999999999999999" should appear as 0x9999999999999999 numeric value. You can specify the base in BigInteger constructor. BigInteger bi = new BigInteger("9999999999999999", 16); String s = bi.toString(16); If the String always starts with "0x" and is hexadecimal: String str = "0x9999999999999999"; BigInteger number = new BigInteger(str.substring(2)); better, check if it starts with "0x" String str = "0x9999999999999999"; BigInteger number; if (str.startsWith("0x")) { number = new BigInteger(str