https://projecteuler.net/problem=33
しらみつぶしするだけですね。
#################### library #################### fn gcd(n: Int, m: Int) -> Int: if m == 0: return n else: return gcd(m, n % m) #################### process #################### fn f() -> Int: var num = 1 var den = 1 # ab/bc = a/c for a in range(1, 10): for b in range(1, 10): var ab = a * 10 + b for c in range(1, 10): var bc = b * 10 + c if ab * c == bc * a: num *= a den *= c var d = gcd(num, den) num //= d den //= d return den fn main() raises: print(f())