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.
8
votes
2answers
120 views
Simple function to verify if a number is integer
Sometimes, there's the need to verify if a given number is an integer or a decimal. Since JavaScript doesn't distinguish between both, I've made an extremelly basic function.
...
18
votes
4answers
10k views
Counting number of 1's and 0's from integer with bitwise operation
Is there a better way of doing this?
...
5
votes
2answers
53 views
Add two numbers stored as a list in F#
I am solving the following problem:
You are given two lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the ...
12
votes
3answers
744 views
Safe multiplication of two 64-bit signed integers
The function below implements safe multiplication of two 64-bit signed integers, preventing overflow from occurring:
...
5
votes
3answers
627 views
Function that adds two integer strings
I wrote this method that adds two integers in the form of strings together. This way I can add large integers without overflowing.
How efficient is the code that I wrote? I am by no means a great ...
6
votes
2answers
77 views
Finding the Greatest Integer and Ties
I'm trying to find the greatest integer of four integers and its ties. I used the following code. Is there anyway to simplify this?
...
7
votes
3answers
7k views
Simpler method to detect int overflow
To detect int overflow/underflow in C, I use the below code.
What might be simpler and portable code? (that is: fewer tests)
Assume 2's complement and don't ...
2
votes
3answers
90 views
Method that returns an integer chosen by user
Can I make this:
if (oneFour == 1 || oneFour == 2 || oneFour == 3 || oneFour == 4)
shorter, especially if I'm gonna need a wider range of integers?
Do I need to ...
4
votes
3answers
197 views
Counting words, letters, average word length, and letter frequency
I'm pretty sure my code is mostly correct. I think I'm having formatting errors more than anything. I keep receiving warnings about "double to float and int to float,possible loss of data. Here is ...
10
votes
2answers
342 views
Convert Persian digits to English numbers
I use the following code to convert ۱۲۳۴۵ to 12345, effectively transliterating the persian numbers into latin numbers:
...
4
votes
3answers
1k views
Decimal/binary/hex converter
I've finally finished my converter and have determined that it works, but I'm trying to make it cleaner and/or more practical (primarily with the switch ...
7
votes
1answer
91 views
IntModulus long addition and subtraction
One of the remarks in this answer to my question concerning IntModulus says
What's more problematic is that you don't have matching argument symmetry for add ...
13
votes
2answers
238 views
Modular arithmetic
As the name says, LongModulus is a pretty long (lengthy) class implementing modular arithmetic for a long modulus. As overflow ...
1
vote
2answers
156 views
Bignum library with arbitrary bases
I just started development on a new bignum library that can operate on numbers of any arbitrary base (up to 232). I want to get a good idea of where I can improve before taking things any further. ...
6
votes
2answers
102 views
IntModulus reloaded
As my question Modular arithmetic was hard to review and terribly long, I've added a few comments to the easier part, namely IntModulus.
The code uses Guava and ...
5
votes
3answers
183 views
K&R 4-12 recursive converter int to string
The exercise is:
Adapt the ideas of printd to write a recursive version of itoa; that
is, convert an integer into a string by calling a recursive routine.
I wonder if I have correctly ...
12
votes
2answers
182 views
UIntArray class in PHP (part 2)
This question is the follow up of the question:
UIntArray class in PHP
@Brythan provided a really nice review and I have improved my class.
I have addressed almost all the issues he pointed out ...
4
votes
2answers
65 views
Test if arithmetic operation will cause undefined behavior
I've written a command line calculator as an exercise to get ready for my upcoming first programming job. The whole program source is around 450 lines of code, which I think is too long for a single ...
7
votes
2answers
326 views
Writing data of a certain integer type to a buffer
I have function which writes data of a specified type to a buffer. Here is the part of this which writes Uint8, Uint16, ...
5
votes
1answer
86 views
Saturated arithmetic
For project Euler, I need quite often to test things like is x*y*z < 1e18. Since BigInteger is usually too slow, ...
1
vote
0answers
34 views
Big Integers and parallel execution with OpenMP
This is part of an implementation of Rabin-Williams signatures as described by Bernstein in Section 6 of "RSA signatures and Rabin–Williams signatures: the state of the art" using Tweaked Roots.
The ...
5
votes
2answers
5k views
Separate numbers with commas
How should I approach refactoring this code?
...
2
votes
2answers
148 views
Float string to integer string
I have a float in the String strFloat. I wanted to convert it to a rounded integer also stored in a ...
2
votes
0answers
92 views
A better way to multiply and add big numbers represented with strings
I got a very unusual problem of adding and multiplying very big numbers (≥1e+100). So I've written simple functions that would operate on string representations of numbers, both as an input and an ...
3
votes
2answers
101 views
Mystery sum with placeholder digits
I came across this coding problem.
Back in primary school, maybe you were sometimes asked to solve a
fill-in-the-blank sum - or "mystery sum" - in which certain digits are
removed and you had ...
3
votes
1answer
44 views
Arbitary Precision Addition
I made a bigint class that can add unsigned unlimited precision integers by splitting number into chunks less than 9999, and if a part is bigger than 9999 I take mod 10000 and carry 1 to the next ...
3
votes
2answers
267 views
HackerEarth Girlfriend's Demand challenge, solved two ways
I solved the Girlfriend's Demand challenge on HackerEarth. In summary:
Input: First line of the input contains a string S. Next line contains an integer Q, the number of queries. Each of the ...
3
votes
3answers
292 views
Mockup in C of hardware implementation for multiplication of signed integers
I challenged myself to implement multiplication of signed integers using only +, -, ...
6
votes
1answer
72 views
Having fun with JNI: formatting a number
I attempted some (easy) coding with Java Native Interface. This is what I have:
six_pack_Neatifier.h:
(autogenerated by javah)
...
4
votes
1answer
185 views
Bills and coin denomination program
I am currently in an intro C++ programming class. We have an assignment where we have to convert a dollar and cents amount, say $192.89, to bills and coins using the least amount of both. Below is the ...
2
votes
1answer
72 views
SPOJ problem - The last digit of a number to a power
Here is the problem statement:
Given integers \$a\$ (\$0 \le a \le 20\$) and \$b\$ (\$0 \le b \le 2,147,483,000\$), where \$a\$ and
\$b\$ are not both 0, find the last digit of \$a^b\$.
...
10
votes
3answers
133 views
Fastest sum of absolute values of 32 differences
A long should be treated as a list of 32 unsigned numbers, each of them just two bit long. So 0x1234F... represents
...
5
votes
3answers
761 views
Number to words problem
This is a very long solution I've been working on to a Number to Words problem. I've identified that there's a lot of repeating logic (e.g. 'if writing > 0', 'writing = integer /',).
How would you ...
3
votes
2answers
82 views
Given bit strings, perform a bitwise addition
I'm looking for code-review, optimizations and best practices. This code is a Java adaptation of code on geeksforgeeks.org. Please verify if space complexity is \$O(n)\$ where n is number of bits, and ...
4
votes
3answers
337 views
Truncating integer using string manipulation
I have a class with a data member that needs to be rounded up to a 2 digit integer, irrespective of the number of the input digits.
For example:
...
9
votes
1answer
427 views
Mostly portable 128 by 64 bit division
I wrote this out of curiosity. It is based on the theory behind Knuth's Algorithm D and is intended to emulate the behavior of the x86 div instruction (though the ...
1
vote
1answer
316 views
Conversion functions between binary, hexadecimal and ASCII
I've written a small suite to easily convert my data between binary, hexadecimal and ASCII:
...
5
votes
3answers
278 views
Performing several integer division operations on an array
Program:
Given an array A of size N. Given Q operations, each operation
contains an integer D. In each operation you have to divide all the
elements of the array by D.
For example, ...
5
votes
3answers
238 views
atoi implementation in C
I'm looking for feedback on my atoi implementation here in C. Any feedback would great. I made my own atoi for fun and to learn ...
7
votes
2answers
698 views
5
votes
2answers
61 views
Distinguishing user input numbers and characters
I am currently taking a computer science class in high school, and it is my first time programming (2 weeks since I started). I have currently finished my program; however, there were a few details ...
8
votes
3answers
270 views
Keeping integer addition within bounds
I have to read a int8_t from a buffer, read a uint8_t from the camera's current settings, add them together, keep new value ...
3
votes
2answers
54 views
Program to evaluate powers of complex numbers
I'm trying to develop a simple program to evaluate integral powers of a complex number \$z\$ , that is, \$z^n\$, where \$z\$ is in the algebrical form \$a+i b\$ and \$n \in \mathbb{Z} ^{*} _{+}\$.
...
4
votes
1answer
118 views
Pollard p - 1 implementation
I'm trying to implement the Pollard p - 1 algorithm seen here, in Java.
It has a C implementation here. I am using it for numbers without any smaller factors so trial factorisation isn't needed. My ...
3
votes
1answer
97 views
Network byte order to host byte order
While doing a little project involving sniffing packets, I found myself programming a cross platform network to host byte order and host to network byte order, this is my first time developing a ...
5
votes
2answers
103 views
Integers from scratch in Haskell
Inspired by this article about natural numbers from first principles in swift I implemented integers from scratch in Haskell.
Besides obviously being extremely inefficient, is this code idiomatic ...
3
votes
1answer
57 views
Parsing a long without using inbuilt function parseLong
I came across it as a problem to solve. What kind of limitations are there?
...
3
votes
1answer
53 views
Fast power in Go
I just started learning Go. To start playing with it, I've implemented the fast power algorithm:
Any suggestions or criticisms regarding the coding style?
...
4
votes
3answers
260 views
Partition a list of numbers into even and uneven numbers
Input: An array of integers.
Output: That same array, but with the even numbers at the front and the uneven numbers at the back of the array.
I wrote three different solutions, depending on the ...
1
vote
1answer
33 views
Counting how many LCD segments are needed to display a number [closed]
I made a program which reads digits of series of numbers and then tells you which would need the largest number of "lines" to be written with a classic digital calculator (example: for 1 you need two ...
