Data type to store a 33 digit wide number in C?

Question

What is the data type that i should use to store a 33 digit wide number. I am using unsigned long long but overflow occurs.How to deal with it?

Strictly speaking this is a subset. `char[33]` is a reasonable answer here, but unsuited for arithmetic. — MSalters, Dec 11 '14 at 15:45
When you are saying "digit" what do you mean? Binary? Hexadecima? Decimal? — Eugene Sh., Dec 11 '14 at 15:58

vz0 · Answer 1 · 2014-12-11T15:58:57.773

1

__int128 on GCC allows you to store numbers up to 170141183460469231731687303715884105727, with 39 digits.

edited Dec 11 '14 at 15:58

answered Dec 11 '14 at 15:49

vz0

1

Isn't that `unsigned __int128`? https://gcc.gnu.org/onlinedocs/gcc/_005f_005fint128.html – pmg Dec 11 '14 at 15:52
@pmg (1<<128) - 1 = (1<<0) + (1<<1) + (1<<2) + ... + (1<<127) = 340282366920938463463374607431768211455. – vz0 Dec 11 '14 at 15:54
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`1<<127` is UB for 128-bit wide signed integers – pmg Dec 11 '14 at 15:55
@pmg Argh, you're correct. In fact is (1<<127) - 1. Thanks – vz0 Dec 11 '14 at 15:58
Remark: This is not portable; most other compilers do not provide a built in 128 bit type. – fuz Dec 11 '14 at 17:03
which header file do i need to include for that??? and how can i print this number using printf?? – user3283576 Dec 11 '14 at 19:00

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