use std::collections::HashMap; fn get_hs(n: u32) -> HashMap { let mut nn = n; let mut res = HashMap::::new(); while nn > 0 { let c = (nn%10) as u8; if res.contains_key(&c) { res.insert(c, res[&c] + 1); } else { res.insert(c, 1); } nn /= 10; } return res; } fn test(n: u32) -> bool { let hm = get_hs(n); for i in 2..=6 { let m = n * i; let hmi = get_hs(m); if hmi != hm { return false; } } return true; } fn main() { for i in 1..999999 { if test(i) { println!("{}", i); break; } } }