Readable C Program to Compute Pi DigitsPublic

For arbitrary precision in C, the shortest practical way is to use MPFR (with GMP under the hood).

Build

Run

This gives n digits after the decimal point, with precision limited only by memory/time (i.e., arbitrary precision).

Great constraint 👍 — readable, pure C, no external libs, arbitrary number of digits (limited by time/RAM).

This uses a classic spigot algorithm for π:

Compile/run:

If you want, I can also give an even shorter version (still readable) with fewer checks/comments.

Done — I wrote it to:

• pi.c

You can compile and run with:

Here’s a tiny C program (single line in main) that prints π with n digits after the decimal point:

Compile and run:

This is very short, but note: precision is limited by long double (so it won’t give thousands of correct digits).