Question

I have taken some courses in c/c++ and I understand that int type size is limited according to CPU architecture.

For 32bit the maximum value of int is 2^32 ( 4,294,967,295 ), but when I use calculator or excel i get huge number and great than 2^32 .

I am really don’t understand this detail how this programs print value great great than 2^23 value .

Answer 1

You can still use values larger than 32 bits in a 32 bit system. In fact, there are BIGINT libraries (like GMP) that allow you to use arbitrarily large integers. These large numbers simply have to be handled in software rather than hardware.

[x86-specific example] Where a simple 32-bit addition uses the add instruction, which adds two 32-bit registers, a 64-bit or BIGINT addition requires the numbers to be added 32 bits at a time, manually propagating the carry from one addition to the next.

See also:

• How to implement big int in C++
• storing big numbers in c++ or c