fn getline() -> String { let mut ret = String::new(); std::io::stdin().read_line(&mut ret).unwrap(); ret } fn factorize_with_prime_factors(mut x: usize) -> Vec { let mut p = 2; let mut ans = vec![]; while p * p <= x { let mut e = 0; while x % p == 0 { x /= p; e += 1; } if e > 0 { ans.push(p); } p += 1; } if x > 1 { ans.push(x); } ans } // https://yukicoder.me/problems/no/3001 (3) // -> TLE。全ての約数ではなく全ての素因数を見るべきかもしれない。素因数 p に対して周期が n/p であるものを調べる。 fn main() { let s = getline().trim().chars().collect::>(); let n = s.len(); let ps = factorize_with_prime_factors(n); let mut ans = (n + 1, 0); for p in ps { let d = n / p; if n % d != 0 { continue; } let mut tot = 0; for i in 0..d { let mut f = [0; 26]; for j in 0..n / d { let c = s[j * d + i] as u8 - b'A'; f[c as usize] += 1; } tot += n / d - *f.iter().max().unwrap(); } ans = ans.min((tot, d)); } let d = ans.1; let mut ans = vec!['+'; n]; for i in 0..d { let mut f = [0; 26]; for j in 0..n / d { let c = s[j * d + i] as u8 - b'A'; f[c as usize] += 1; } let idx = f.iter().enumerate().max_by_key(|&(_, v)| v).unwrap().0; let c = (b'A' + idx as u8) as char; for j in 0..n / d { ans[j * d + i] = c; } } println!("{}", ans.into_iter().collect::()); }