Someone asked me a question via e-mail about integer partitions the other day (as I had released a Perl module, Integer::Partition, to generate them), that I was unable to answer. Background: here are all the integer partitions of 7 (the sum of each row equals 7). 7 6 1 5 2 5 1 1 4 3 4 2 1 4 1 1 1 3 3 1 3 2 2 3 2 1 1 3 1 1 1 1 2 2 2 1 ...
I need to compare the integer part of two doubles for inequality and I'm currently doing this: int iA = (int)dA; int iB = (int)dB; if( iA != iB ) { ... } but I wonder if there's a better approach than this. Thanks. If I used Math.Truncate() instead of a cast to int, would it still be accurate to compare the two resulting double...
Am I correct to say the difference between a signed and unsigned integer is: UnSigned can hold a larger positive value, and no negative value. Unsigned uses the leading bit, while the signed version uses the left-most-bit to identify if the number is positive or negative. signed integers can hold both positive and negative numbers. A...
We have a file that has a 64 bit integer as a string in it. How do we scanf() or otherwise parse this numeric string into an unsigned 64 bit integer type in C++ ? We are aware of things like %lld etc., but a lot of ways to do this parse seem to break compiles under different compilers and stdlibs. The code should compile under gcc and ...
I need to be able to compare some month names I have in an array. It would be nice if there were some direct way like: Month.toInt("January") > Month.toInt("May") My Google searching seems to suggest the only way is to write your own method, but this seems like a common enough problem that I would think it would have been already imp...
I want to be able to process arbitrarily large numbers in C#. I can live with just integers. Are there established algorithms for this kind of thing? Or is there a good 3rd-party library? I might consider changing language if there really is no good way to do it in C#. Thanks for any help / suggestions. ...
Problem: I have an integer; this integer needs to be converted to a stl::string type. In the past, I've used stringstream to do a conversion, and that's just kind of cumbersome. I know the C way is to do a sprintf, but I'd much rather do a C++ method that is typesafe(er). Is there a better way to do this? Here is the stringstream ap...
I need to have a string, based on an integer, which should always have 5 digits. Example: myInteger = 999 formatedInteger = "00999" What is the best way of doing this in classic ASP? ...
I found this in the code I'm working on at the moment and thought it was the cause of some problems I'm having. In a header somewhere: enum SpecificIndexes{ //snip INVALID_INDEX = -1 }; Then later - initialization: nextIndex = INVALID_INDEX; and use if(nextIndex != INVALID_INDEX) { //do stuff } Debugging the code, t...
I'm working on a programming language, and today I got the point where I could compile the factorial function(recursive), however due to the maximum size of an integer the largest I can get is factorial(12). What are some techniques for handling integers of an arbitrary maximum size. The language currently works by translating code to ...
I have some HTML I am trying to parse. There are cases where the html attributes alone are not going to help me identify the row type (header versus data). Fortunately, if my row is a data row then it should have some values that can be converted to integers. I have figured out how to convert the unicode to an integer for those cases ...
Hi guys, This is probably pretty basic... but I don't seem to get it: How does (2 & 1) = 0 (3 & 1) = 1 (4 & 1) = 0 etc.. This pattern above seems to help find even numbers or (0 | 1) = 1 (1 | 1) = 1 (2 | 1) = 3 (3 | 1) = 4 (4 | 1) = 5 (5 | 1) = 5 I know how boolean algebra works between bits. But I don't understand how Boolea...
Hi all, I'm trying to encrypt some integers in java using java.security and javax.crypto. The problem seems to be that the Cipher class only encrypts byte arrays. I can't directly convert an integer to a byte string (or can I?). What is the best way to do this? Should I convert the integer to a string and the string to byte[]? Th...
IntToStr() function returns string which is Unicode now. I want converting to AnsiString. Can I use AnsiString(IntToStr(I)) safely? ...
How would you append an integer to a char* in c++? ...
I'm new to using regex and I'd like to use it with Java. What I want to do is find the first integer in a string. Example: String = "the 14 dogs ate 12 bones" Would return 14. String = "djakld;asjl14ajdka;sdj" Would also return 14. This is what I have so far. Pattern intsOnly = Pattern.compile("\\d*"); Matcher makeMatch = intsOnly....
The built-in Math.Pow() function in .NET raises a double base to a double exponent and returns a double result. What's the best way to do the same with integers? Added: It seems that one can just cast Math.Pow() result to (int), but will this always produce the correct number and no rounding errors? ...
I know that modern languages handle integer divide by zero as an error just like the hardware does, but what if we could design a whole new language? Ignoring existing hardware, what should a programming language does when an integer divide by zero occurs? Should it return a NaN of type integer? Or should it mirror IEEE 754 float and ...
What i want is to take an integer represented as a string, for example "1234", and convert it to a file called int, containing a 32-bit big endian integer, with the value 1234. The only way I have figured out to do this is something like echo 1234 | awk '{printf "0: %08X", $1}' | xxd -r > int which is a bit nasty! Does anyone know a...
Some background: If I wanted to use for, for instance, scanf() to convert a string into a standard integer type, like uint16_t, I’d use SCNu16 from <inttypes.h>, like this: #include <stdio.h> #include <inttypes.h> uint16_t x; char *xs = "17"; sscanf(xs, "%" SCNu16, &x); But a more uncommon integer type like pid_t does not have any suc...