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.

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3
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2answers
185 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
249 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
61 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) ...
1
vote
1answer
51 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\$. ...
4
votes
1answer
58 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 ...
8
votes
3answers
122 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 ...
2
votes
2answers
66 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
317 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: ...
1
vote
1answer
75 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
218 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
187 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
3answers
258 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
44 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} ^{*} _{+}\$. ...
5
votes
2answers
51 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 ...
4
votes
1answer
63 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
61 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
92 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
42 views

Parsing a long without using inbuilt function parseLong

I came across it as a problem to solve. What kind of limitations are there? ...
4
votes
3answers
221 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
27 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 ...
2
votes
1answer
61 views

All-in-one number base converter

I coded this program as a challenge for /r/dailyprogrammer. Basically this program can convert any number from any base to another base including negative bases as long as the input is coherent. Did I ...
3
votes
1answer
31 views

Digit Summing Function

I'm working through the common divisibility tests, and implementing them in Racket. I'm working on divisible by three, for which I thought it'd be nice to keep summing until I got to a single digit ...
4
votes
4answers
642 views

Squaring an integer by repetitive addition

I've written two functions: is_integer(), which tries to get a positive or a negative integer as input and returns the same value. ...
2
votes
2answers
72 views

Writing an API for checked subtraction

I have to write an API for checked subtraction where the input minuend can be < 0 but subtrahend can't be < 0. I think I've covered all the cases of underflow and overflow. With given conditions ...
6
votes
4answers
1k views

Swapping two integer numbers with no temporary variable

I tried to swap 2 integer numbers without using an additional variable as a traditional swap. Is it legal in C++? My VC compiler doesn't complain nor gives any warning about it. If so, how can I ...
3
votes
1answer
49 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? ...
3
votes
2answers
70 views

BigRational based on BigIntegers

For Project Euler I've implemented a BigRational. The functionality is rather limited, just things I needed or will probably need soon. The style departs a bit from ...
10
votes
1answer
280 views

Multiplication 128 x 64 bits

I was fooling around with the Collatz sequence a bit and found out that long is only sufficient for starting values below ...
3
votes
3answers
72 views

Listing the representations of integer M as a sum of three squares M = x^2 + y^2 + z^2

I am trying a number as the sum of 3 squares. For my particular project I will require a complete list since the next step is to compute nearest neighbors (here). In any case we'd like to find \$ M ...
6
votes
4answers
560 views

Sum of digits in a^b

I'm trying to calculate a problem which requires sum of digits in \$a^b\$, where \$0 \le a \le 9\$ and \$0 \le b \le 4000\$. I have seen various other posts similar to this, but I haven't acquired ...
9
votes
0answers
132 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 ...
12
votes
3answers
1k views

Random permutation of int[] and ArrayList<Integer>

I wrote a simple program using int[] and ArrayList<Integer> which aims to get a random permutation output between 1 to 10, ...
3
votes
4answers
238 views

Function to extract bytes as a decimal

You give this function a pointer and how many bytes you want to extract as a decimal and it returns it. ...
10
votes
4answers
448 views

Computing the square root of a 64-bit integer

When sieving primes up to some 64-bit number n I need to determine an upper bound for the greatest potential factor of n, which ...
10
votes
1answer
154 views

UIntArray class in PHP

I have seen UInts being natively supported in other languages. PHP allows you to install a third party extension, but I can't do that ATM, so I've decided to create ...
8
votes
4answers
1k views

Computing factorials

I am computing factorials as part of teaching myself C++. I am looking for feedback on efficiency, style and any bad practices I may be using. ...
5
votes
2answers
71 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 more effectively? ...
8
votes
1answer
276 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 ...
10
votes
3answers
593 views

Beginnings of a base-conversion game in Python

I'm pretty very new to python, so I thought that I'd write a game to teach me python and better teach me how to think in hexadecimal and binary. I'm starting off by writing a few functions to convert ...
8
votes
2answers
232 views

Parsing integers safely

Background I'm writing user input validation for a client-side JavaScript web application. Users enter numerals representing an integer into an <input>. As ...
8
votes
2answers
144 views

Lossy packing 32 bit integer to 16 bit

I am working on the lossy 16 bit representation for 32 bit integers that catches all 32 bit range with precision depending on absolute value. My idea is to store integer ...
5
votes
4answers
189 views

C library that converts integers to string and vice-versa

I've created this little library to help ease myself (and for others, hopefully) with the pain of having to convert integers to string and vice-versa. It's written in C, and for maximum portability I ...
2
votes
1answer
257 views

Encoding and decoding exercise

I was issued the following coding challenge from a company to write an encoding and decoding function: Encoding: This function needs to accept a signed integer in the 14-bit range [-8192..+8191] ...
3
votes
2answers
195 views

Emulating __uint128_t

I developed a lot of code locally with __uint128_t only to find out that it is not available on the target platform. I am now trying to write my own struct that ...
0
votes
1answer
124 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. ...
10
votes
3answers
2k views

More elegant way to increment Integers in Map?

I have a HashMap<Token, Integer>, which counts occurrences of Token. Each time Token ...
5
votes
2answers
526 views

Why are these functions slower than BigInteger's included methods?

I tried writing alternative functions to Java's BigInteger.add(BigInteger.ONE), BigInteger.add(BigInteger), and ...
2
votes
1answer
305 views

Tough List Comprehension Split Letters and Numbers

So, another challenge from my professor. I've finished it, but wanted to get some feedback, and see how other people might work this problem. Assume you have a string, such as "Hello 34215 World ...
10
votes
1answer
1k views

Thread-Safe Integer Sequence

I would like to give an Integer to whatever demands it. For that I use the following code ...
3
votes
2answers
282 views

Function for splitting an integer into smaller values

This is the function I've implemented in an answer to this question. I've tried to make this as simple and idiomatic as possible, using C++11. Could this still be improved in any way? ...