Using very big number

Question

I am looking to use very big numbers (up to 255 figures in one variable) and manipulating these values on basic level (+, -, *, /, ^ and √) in C++ but I am not sure whether using bigInt (https://mattmccutchen.net/bigint/) will handle such big numbers.

https://www.google.com/#q=arbitrary+precision+library+c%2B%2B — user2485710, Dec 28 '13 at 10:07
Citing the linked page: _"You can use this library in a C++ program to do arithmetic on integers of size limited only by your computer's memory"_. I bet that your computer has enough memory to handle 255 figures, and even more! But note that this library is only for _integer_, not fractions or decimals, hence the name, — rodrigo, Dec 28 '13 at 10:08

score 2 · Accepted Answer · edited May 23 '17 at 11:51

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Similar to here, I will recommend you to check out The Large Integer Case Study in C++.pdf by Owen Astrachan. I found this file extremely useful with detail introduction and code implementation. It doesn't use any 3rd-party library. I have used this to handle huge numbers (as long as you have enough memory to store vector<char>) with no problems.

Idea: It implements an arbitrary precision integer class by storing big int in a vector<char>.

vector<char> myDigits; // stores all digits of number

Then all operations related to the big int, including <<, >>, +, -, *, ==, <, !=, >, etc., can be done based on operations on this char array.

Edit: Btw, bigInt is fine too.

edited May 23 '17 at 11:51

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answered Dec 28 '13 at 10:16

herohuyongtao

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It _is_ a third-party library. – Lightness Races in Orbit Dec 28 '13 at 13:46
@LightnessRacesinOrbit You mean the one by Owen Astrachan? – herohuyongtao Dec 28 '13 at 13:48
The provided solution was enough to start establishing foundations on my project. The situation is such that the project can be the whole solution so importing 3rd party library is not a problem. I think using such method will do the work. Many thanks! – user3141651 Dec 30 '13 at 07:14
@user3141651 Good to go. :) – herohuyongtao Dec 30 '13 at 07:47

score 1 · Answer 2 · answered Dec 28 '13 at 10:14

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i'll suggest you to use GMP (https://gmplib.org). it's work with arbitrary length numbers.

answered Dec 28 '13 at 10:14

zapredelom

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Using very big number

2 Answers2