Distinct primes factors
Author: Gerhard R
https://projecteuler.net/problem=47
The first two consecutive numbers to have two distinct prime factors are:
14 = 2 × 7 15 = 3 × 5
The first three consecutive numbers to have three distinct prime factors are:
644 = 2² × 7 × 23 645 = 3 × 5 × 43 646 = 2 × 17 × 19.
Find the first four consecutive integers to have four distinct prime factors. What is the first of these numbers?
To run this example, the associated C file (prob047-gerdr.c) needs to be compiled into a shared object library.
In GCC this is achieved like so:
$ gcc --std=c99 -fPIC -c -o prob047-gerdr.o prob047-gerdr.c $ gcc -shared -o prob047-gerdr.so prob047-gerdr.o
After which, the example can be run as expected:
$ perl6 prob047-gerdr.pl
Source code: prob047-gerdr.pl
use v6; use NativeCall; sub factors(int32 $n) returns int32 is native($*SPEC.catdir($*PROGRAM-NAME.IO.dirname, 'prob047-gerdr')) { * } sub MAIN(Int $N = 4) { my int $n = 2; my int $i = 0; while $i != $N { $i = factors($n) == $N ?? $i + 1 !! 0; $n = $n + 1; } say $n - $N; }