#[allow(unused_imports)] use std::cmp::*; #[allow(unused_imports)] use std::collections::*; use std::io::{Write, BufWriter}; const DEBUG: bool = false; const STRESS: bool = false; // https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8 macro_rules! input { ($($r:tt)*) => { let stdin = std::io::stdin(); let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock())); let mut next = move || -> String{ bytes .by_ref() .map(|r|r.unwrap() as char) .skip_while(|c|c.is_whitespace()) .take_while(|c|!c.is_whitespace()) .collect() }; input_inner!{next, $($r)*} }; } macro_rules! input_inner { ($next:expr) => {}; ($next:expr, ) => {}; ($next:expr, $var:ident : $t:tt $($r:tt)*) => { let $var = read_value!($next, $t); input_inner!{$next $($r)*} }; } macro_rules! read_value { ($next:expr, ( $($t:tt),* )) => { ( $(read_value!($next, $t)),* ) }; ($next:expr, [ $t:tt ; $len:expr ]) => { (0..$len).map(|_| read_value!($next, $t)).collect::>() }; ($next:expr, chars) => { read_value!($next, String).chars().collect::>() }; ($next:expr, usize1) => { read_value!($next, usize) - 1 }; ($next:expr, [ $t:tt ]) => {{ let len = read_value!($next, usize); (0..len).map(|_| read_value!($next, $t)).collect::>() }}; ($next:expr, $t:ty) => { $next().parse::<$t>().expect("Parse error") }; } #[allow(unused)] macro_rules! debug { ($($format:tt)*) => (write!(std::io::stderr(), $($format)*).unwrap()); } #[allow(unused)] macro_rules! debugln { ($($format:tt)*) => (writeln!(std::io::stderr(), $($format)*).unwrap()); } /** * Returns the least index of elements that are modified, wrapped with Some. * If the entire array is reversed, it returns None instead. * v's elements must be pairwise distinct. */ fn next_permutation(v: &mut [T]) -> Option { if v.len() == 0 { return None; } let mut tail_dec: usize = 1; let n = v.len(); while tail_dec < n { if v[n - tail_dec - 1] > v[n - tail_dec] { tail_dec += 1; } else { break; } } // v[n - tail_dec .. n] is strictly decreasing if tail_dec < n { let x = n - tail_dec - 1; let mut y = n; { let pivot = &v[x]; for i in (n - tail_dec .. n).rev() { if v[i] > *pivot { y = i; break; } } assert!(y < n); } v.swap(x, y); } v[n - tail_dec .. n].reverse(); if tail_dec < n { Some(n - tail_dec - 1) } else { None } } fn calc_naive(mut a: Vec, p: usize, q: usize) -> Option> { loop { if let None = next_permutation(&mut a) { return None; } let pidx = a.iter().position(|&x| x == p).unwrap(); let qidx = a.iter().position(|&x| x == q).unwrap(); if pidx < qidx { return Some(a); } } } fn calc(mut a: Vec, p: usize, q: usize) -> Option> { let n = a.len(); if let None = next_permutation(&mut a) { return None; } let pidx = a.iter().position(|&x| x == p).unwrap(); let qidx = a.iter().position(|&x| x == q).unwrap(); if pidx < qidx { return Some(a); } if DEBUG { eprintln!("p,q = {}, {}", pidx, qidx); } // qidx < pidx. Try to increment a[qidx]. a[qidx + 1..].sort(); a[qidx + 1..].reverse(); if DEBUG { eprintln!("a = {:?}", a); } if let None = next_permutation(&mut a) { return None; } let pidx = a.iter().position(|&x| x == p).unwrap(); let qidx = a.iter().position(|&x| x == q).unwrap(); if pidx < qidx { return Some(a); } if p > q { // ? ... ? 0 1 ... q x y p ... (increasing from 0) if DEBUG { eprintln!("pqa = {} {} {:?}", p, q, a); } // Turns into ? ... ? 0 1 ... x y p q ... for i in qidx..pidx { a.swap(i, i + 1); } Some(a) } else { // ? ... ? q 0 1 ... p ... (increasing from 0) assert!(p < q); if DEBUG { eprintln!("pqidx = {} {}, a = {:?}", pidx, qidx, a); } let mut ma = 0; // max of the rightmost part for i in qidx + 1..n { ma = max(ma, a[i]); } if ma > q { a[qidx + 1..].reverse(); next_permutation(&mut a).unwrap(); return Some(a); } // We want q to be in the rightmost "sorted" part. // When will it happen? let mut rem = BTreeSet::new(); for i in 0..n { rem.insert(i); } let mut poss = vec![]; for i in 0..qidx { rem.remove(&a[i]); let mut it = rem.range(a[i] + 1..); let mut res = it.next(); // Ignoring q if res == Some(&q) { res = it.next(); } if let Some(&to) = res { poss.push((i, to)); } } if poss.is_empty() { return None; } let &(idx, to) = poss.last().unwrap(); let toidx = a.iter().position(|&x| x == to).unwrap(); a.swap(idx, toidx); a[idx + 1..].sort(); Some(a) } } fn solve() { let out = std::io::stdout(); let mut out = BufWriter::new(out.lock()); macro_rules! puts { ($($format:tt)*) => (let _ = write!(out,$($format)*);); } input! { n: usize, p: usize1, q: usize1, a: [usize1; n], } if let Some(ans) = calc(a, p, q) { for i in 0..n { puts!("{}{}", ans[i] + 1, if i + 1 == n { "\n" } else { " " }); } } else { puts!("-1\n"); } } fn stress() { for n in 2..7 { for p in 0..n { for q in 0..n { if p == q { continue; } let mut a: Vec = (0..n).collect(); loop { let ans_naive = calc_naive(a.clone(), p, q); let ans = calc(a.clone(), p, q); if ans != ans_naive { eprintln!("a = {:?}, p = {}, q = {}\n ex = {:?}, act = {:?}", a, p, q, ans_naive, ans); } if let None = next_permutation(&mut a) { break; } } } } } } fn main() { if STRESS { stress(); } else { solve(); } }