Use this tag for questions about using, storing or manipulating integral values of all types and sizes, including concerns about overflow. Not for code that casually happens to use integers.
6
votes
1answer
42 views
Storing angles with overflow errors
Rather than checking if my angle is in the range of 0 to 2pi every time it gets set, I got the idea to store it as an unsigned short with 0xFFFF being +2pi, thus the standard overflow behavior for ...
4
votes
1answer
81 views
Enforcing correct input/output of integers
The problem:
Some types, like cstdint aliases or, at least purely theoretically, even std::size_t, may be (but don’t have to be)...
10
votes
3answers
479 views
Counting the number of “on” bits in an int
Here is some code I wrote as a solution to Programming Exercise 15.3 in Stephen Prata's C Primer Plus, 6th Edition. It is probably worth pointing out that the title of the chapter is Bit Fiddling. The ...
2
votes
1answer
63 views
Number representation for a calculator that works with very big numbers
I'm a beginner: I have learned concepts and features which I think I need in my project, but this is my first serious program and it is my internship project. I'm totally confused and need help to ...
3
votes
1answer
101 views
Maximum product of 3 integers in an int array using Python - follow up
This is a follow up to Maximum product of 3 integers in an int array using Python
Changes to the code include renamed variables for improved readability and I added more test cases.
...
3
votes
5answers
159 views
Maximum product of 3 integers in an int array using Python
This is an interview question from Interview Cake:
Given a list_of_ints, find the highest_product you can get from three of the integers.
The input list_of_ints will always have at least three ...
-2
votes
1answer
44 views
Construct: VarInt integer encoding
This code is part of the Construct library. Docstrings explain what the code is supposed to do.
...
1
vote
1answer
40 views
Using strtol() follow up
Link to original question: Successful use of strtol() in C
After getting excellent feedback from the code review community I attempted to redo my string to long conversion program! I believe I ...
3
votes
1answer
36 views
Program to determine ranges of char, short, int and long variables, both signed and unsigned
I wrote code to determinate ranges of char,short int and long variables,both signed and unsigned.Please help me to improve my code :) Here is the code:
...
10
votes
3answers
918 views
Successful use of strtol() in C
Attempted to use strtol() to parse a string into an integer and to output any appropriate error messages for failed conversions. How did I do? How could/should it ...
5
votes
1answer
85 views
Converting a bytearray into an integer
I am working on a program to decode MMS PDU files. They are binary files and I am reading them byte by byte and decoding each header value as I come to it.
One header value is the Date, and it's ...
4
votes
1answer
52 views
Integer-to-ASCII algorithm (x86 assembly)
This is my best effort at converting a 32 bit integer in EAX, to an 8 character ascii string (result in RDI). It will work ...
4
votes
3answers
96 views
Dividing Negative integer ranges
Context:
My project has a hand-rolled ORM (... yeah ... I know) ...
built around the MS DataSet objects that represent wrapped collections of rows of DBtables (... yeah ... I know) ...
and which ...
3
votes
2answers
92 views
Converting bits to decimal (integer) string is so slow
I am implementing myself a BigInteger class. It can natively handle very very big digits in very short time.
...
1
vote
2answers
52 views
Finding shortest sequences of integers whose product is larger than n
Here is the task:
For an integer n, return a list of the k length integers sequences whose product is larger than n but as close to n as possible (i.e. smallest larger than n number), and whose ...
1
vote
1answer
63 views
Translating binary data from a file into a very large base-ten integer
I'm making an experimental Java algorithm that translates binary data from a file into a (very large) base ten integer. I am using BigInteger since this number may ...
6
votes
2answers
62 views
Valid memory address in Python
I am looking for suggestions of improving this function to check whether a memory address is appropriate or not.
...
4
votes
2answers
58 views
Adding two binary-coded-decimal numbers
I want to make some VHDL code open source. But before I do, I want to make sure that it is as readable as possible. Things to improve upon could for example be naming and the use of comments.
The ...
4
votes
3answers
145 views
0
votes
0answers
31 views
Bit twiddling utils for Int and Long classes
I added some bit twiddling utils to Int and Long classes in Scala but I have highly duplicated code. Is there a way to DRY this?
...
7
votes
1answer
162 views
Variable length integer encoding in Java
I have coded up the variable length integer encoding aka VLQ in Java. It works with any base in (1, 128]. I've implemented the usual encode/decode methods and also ...
5
votes
2answers
58 views
Number class to add/compare different kinds of numbers
I am creating a Number class having Integer and Fraction derive class which add/compare different kinds of numbers. In addition, the caller need not needs to know ...
2
votes
2answers
39 views
Dividing a long (arbitrary-precision) number by an integer
As part of a (slightly) larger program, I needed to write a function that could take an arbitrarily large number and divide it by a small number. In this program, I will be dividing this number ...
0
votes
2answers
64 views
Convert NSInteger into NSString
This is my sample code to convert a integer into string.
Is it very costly to do the multiple loops of [NSMutableString stringWithFormat:..]?
I.e should I just use appendString and get the NSString ...
5
votes
2answers
391 views
itoa base function in C
This is a function that converts an integer value to a null-terminated string using the specified base and stores the result in a char array that I must allocate (...
2
votes
1answer
57 views
Avoiding “warning: Use of uninitialized value” when fetching an integer CGI parameter
I was using this code to fetch a CGI parameter:
$page = int(param('page'));
This sometimes results in:
...
4
votes
1answer
111 views
Normalize integer types to float range
I wrote two template functions to take an integer type and output a float in the given range. One function takes signed integers and the other takes unsigned ...
3
votes
2answers
67 views
Merge and sorting arrays of String and int in more efficient methods
Are there better methods for merge and sorting arrays of int and String in more efficient methods both time-complexity wise and ...
3
votes
1answer
108 views
Handling GetTickCount() overflow in timeouts
This is code which must run on XP, so no GetTickCount64, and which should correctly handle the value wrapping around after 49 days. Can it be improved?
...
4
votes
1answer
52 views
LEB128 in Haskell
I have implemented the LEB128 encoding for unsigned integers. I'm fairly new to Haskell so I have some doubt about the coding style I'm using, particularly the definition of ...
8
votes
1answer
121 views
2
votes
2answers
77 views
Calculating the sum of the digits in 2^1000
I have a program which calculates the sum of the digits in the number 21000. The program is not beautiful and I was hoping for some advice on how to improve it.
The idea I have used is to create an ...
2
votes
1answer
78 views
String-casting utility functions
I wrote a small header that is supposed to take care of calling the right strtoX or or stoX function for me and doing so at ...
5
votes
1answer
59 views
`read` re-implemented for Int's
I have written a safe read function for haskell (for education!). I think this is fairly idiomatic haskell code, but I'd like to know for sure. If you see anything else that could be improved, please ...
3
votes
2answers
263 views
Get number from N
I'm trying to find the shortest and best way to achieve the following:
Given input integer $N, get the following output:
n = 0, output = 0
n = 1, output = 0
n = 2, output = 10
n = 3, output = 100 ...
10
votes
1answer
138 views
Corrupting Java arithmetic through reflection
Inspired by a PPCG answer, I wrote this code, which shuffles the autoboxing caches of Number subclasses.
This leads to, among other things, outputting ...
3
votes
1answer
52 views
Comparing a string that can hold a numeric value
I am refactoring a part of big old system developed in Java. I came across a situation where we are migrating some data types, and there will be use of both types. For compatibility, as all the old ...
6
votes
1answer
130 views
Large integer class for storing integer data as a char array
I am working on a LargeInteger class to store Integers beyond the size of long long as a dynamic character array. I have ...
2
votes
1answer
488 views
Simple calculation program in assembly MASM
I am a beginner in assembly. This program calculates:
(Z+Z)+(X-Y)
...
1
vote
2answers
84 views
Concatenate three 16-bit integers in one 64-bit integer with C++
I am looking for an elegant alternative of the following code where wordXX contains always 16 bits:
...
7
votes
2answers
72 views
Portable byte order conversion
I'm trying to improve the portability of a file format converter, specifically to POSIX platforms other than Linux. I'd appreciate a review of the following functions used for converting between ...
2
votes
2answers
109 views
Python combine two integers to a third
We have three integers:
A, B, C where the first (i.e. the most significant) digit of C is the first digit of A, the second digit of C is the first digit of B, the third digit of C is the second ...
5
votes
1answer
86 views
Safe, fully standards-following integer abs in C
Here's a bit tricky one, because AFAIK there is no existing platform, where conditionally compiled part of the code would actually get included by compiler, so it is entirely up to the human review to ...
4
votes
0answers
69 views
Multiple base numbers parser
This code is a Parser that parses numbers according to R5RS.
#b1001 - binary
#o2127 - octal
#h02d - hexadecimal
#d1231 - decimal
3923 - decimal
It is working ...
3
votes
1answer
55 views
Turning an Integer into an array of ints
My goal here is pretty simple, I want to turn a number like 12435987234 into an array of integers in reverse order. So that would look like:
...
11
votes
4answers
1k views
Arabic to Greek numeral converter, 1 - 10
One of the things that's straight-forward in JavaScript is Unicode support. If you want to return ϝ (lowercase digamma, not a simple ...
4
votes
3answers
84 views
Convert a number into a different base and return as string
I wanted to write a function that would take a long long int argument as well as a base and it would convert that number into an equivalent number in a different ...
11
votes
4answers
654 views
Detecting arithmetic overflow in C with NASM
This snippet is about detecting whether the carry flag is set or cleared. I work on Mac OSX, so my snippet supports Mac only.
First, we need a routine that does the job:
func.s:
...
12
votes
6answers
2k views
Converting a string to an Integer in C
I'm learning C and one of the questions I've been asked is converting a string to an integer. The code I've written supports converting from a string in any base up to 16/hex to an integer. There is ...
17
votes
2answers
645 views
Fast 32x32 bit multiply on ARM M0
I have a time-critical calculation running on an ARM Cortex-M0. This is the fastest 32x32 bit -> 64 bit multiplication that I can come up with.
The following C compiles almost 1-1 to assembly ...
