Problem:
Score : 800 points

Problem Statement

You are given integers N,\ A and B.
Determine if there exists a permutation (P_0,\ P_1,\ ...\ P_{2^N-1}) of (0,\ 1,\ ...\ 2^N-1) that satisfies all of the following conditions, and create one such permutation if it exists.

P_0=A

P_{2^N-1}=B

For all 0 \leq i < 2^N-1, the binary representations of P_i and P_{i+1} differ by exactly one bit.

Constraints

1 \leq N \leq 17

0 \leq A \leq 2^N-1

0 \leq B \leq 2^N-1

A \neq B

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N A B

Output

If there is no permutation that satisfies the conditions, print NO.

If there is such a permutation, print YES in the first line.
Then, print (P_0,\ P_1,\ ...\ P_{2^N-1}) in the second line, with spaces in between.
If there are multiple solutions, any of them is accepted.

Sample Input 1

2 1 3

Sample Output 1

YES
1 0 2 3

The binary representation of P=(1,0,2,3) is (01,00,10,11), where any two adjacent elements differ by exactly one bit.

Sample Input 2

3 2 1

Sample Output 2

NO

Solution in Rust (1.15.1) (judge verdict: Runtime Error)

/*------------------------------------------------------------------*/
/*------------------------- begin template -------------------------*/
/*------------------------------------------------------------------*/

// ref: tanakh <https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8>
// diff: using Parser
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut parser = Parser::from_str($s);
        input_inner!{parser, $($r)*}
    };
    (parser = $parser:ident, $($r:tt)*) => {
        input_inner!{$parser, $($r)*}
    };
    (new_stdin_parser = $parser:ident, $($r:tt)*) => {
        let stdin = std::io::stdin();
        let reader = std::io::BufReader::new(stdin.lock());
        let mut $parser = Parser::new(reader);
        input_inner!{$parser, $($r)*}
    };
    ($($r:tt)*) => {
        input!{new_stdin_parser = parser, $($r)*}
    };
}

macro_rules! input_inner {
    ($parser:ident) => {};
    ($parser:ident, ) => {};
    ($parser:ident, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($parser, $t);
        input_inner!{$parser $($r)*}
    };
}

macro_rules! read_value {
    ($parser:ident, ( $($t:tt),* )) => {
        ( $(read_value!($parser, $t)),* )
    };
    ($parser:ident, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($parser, $t)).collect::<Vec<_>>()
    };
    ($parser:ident, chars) => {
        read_value!($parser, String).chars().collect::<Vec<char>>()
    };
    ($parser:ident, usize1) => {
        read_value!($parser, usize) - 1
    };
    ($parser:ident, i64_) => {
        $parser.fast_i64()
    };
    ($parser:ident, usize_) => {
        $parser.fast_i64() as usize
    };
    ($parser:ident, usize1_) => {
        ($parser.fast_i64() - 1) as usize
    };
    ($parser:ident, $t:ty) => {
        $parser.next::<$t>().expect("Parse error")
    };
}

use std::io;
use std::io::BufRead;
use std::str;

// ref: tatsuya6502 <https://qiita.com/tatsuya6502/items/cd448486f7ef7b5b8c7e>
// ref: wariuni <https://qiita.com/tatsuya6502/items/cd448486f7ef7b5b8c7e#comment-7040a5ae96305e884eb9>
// diff: using std::io::BufRead::fill_buf()
pub struct Parser<R> {
    pub reader: R,
    buf: Vec<u8>,
    pos: usize,
}

impl Parser<io::Empty> {
    pub fn from_str(s: &str) -> Parser<io::Empty> {
        Parser {
            reader: io::empty(),
            buf: s.as_bytes().to_vec(),
            pos: 0,
        }
    }
}

impl<R: BufRead> Parser<R> {
    pub fn new(reader: R) -> Parser<R> {
        Parser {
            reader: reader,
            buf: vec![],
            pos: 0,
        }
    }
    pub fn update_buf(&mut self) {
        self.buf.clear();
        self.pos = 0;
        loop {
            let (len, complete) = {
                let buf2 = self.reader.fill_buf().unwrap();
                self.buf.extend_from_slice(buf2);
                let len = buf2.len();
                (len, buf2[len - 1] <= 0x20)
            };
            self.reader.consume(len);
            if complete {
                break;
            }
        }
    }
    pub fn next<T: str::FromStr>(&mut self) -> Result<T, T::Err> {
        loop {
            let mut begin = self.pos;
            while begin < self.buf.len() && (self.buf[begin] <= 0x20) {
                begin += 1;
            }
            let mut end = begin;
            while end < self.buf.len() && (self.buf[end] > 0x20) {
                end += 1;
            }
            if begin != self.buf.len() {
                self.pos = end;
                return unsafe { str::from_utf8_unchecked(&self.buf[begin..end]) }.parse::<T>();
            } else {
                self.update_buf();
            }
        }
    }
    pub fn fast_i64(&mut self) -> i64 {
        loop {
            let mut begin = self.pos;
            while begin < self.buf.len() && (self.buf[begin] <= 0x20) {
                begin += 1;
            }
            if begin == self.buf.len() {
                self.update_buf();
                continue;
            }
            let mut res = 0;
            let (is_positive, mut end) = match self.buf[begin] {
                b'+' => (true, begin + 1),
                b'-' => (false, begin + 1),
                _ => (true, begin),
            };
            while end < self.buf.len() && (self.buf[end] > 0x20) {
                res = res * 10 + (self.buf[end] as i64 - '0' as i64);
                end += 1;
            }
            if begin != self.buf.len() {
                self.pos = end;
                return if is_positive { res } else { -res };
            } else {
                self.update_buf();
            }
        }
    }
}

#[allow(unused_imports)]
use std::cmp::*;

fn main() {
    input! {
        new_stdin_parser = parser,
    }
    let res = solve(&mut parser);
    print!("{}", res);
}

/*------------------------------------------------------------------*/
/*-------------------------- end template --------------------------*/
/*------------------------------------------------------------------*/

fn swap_bit(x: i64, i: usize, k: usize) -> i64 {
    (x & !(1 << i) & !(1 << k)) | (((x >> i) & 1) << k) | (((x >> k) & 1) << i)
}

use std::fmt::Write;
fn solve<R: BufRead>(parser: &mut Parser<R>) -> String {
    let mut buf = String::new();
    input! {
        parser = parser,
        n: usize,
        a: i64,
        b: i64,
    }
    let t = a ^ b;
    if t.count_ones() % 2 != 0 {
        let (flip1, flip2) = {
            let (t, mut u) = (n - 1, n - 1);
            for i in 0..n {
                if a & (1 << i) != b & (1 << i) {
                    u = i;
                }
            }
            (t, u)
        };
        let a = swap_bit(a, flip1, flip2);
        let b = swap_bit(b, flip1, flip2);
        // eprintln!("a={:06b}, b={:06b}", a, b);
        let mut xs = vec![0; 1 << n];
        for i in 0..n - 1 {
            let scale = 4i64.pow((i / 2) as u32);
            // eprintln!("i={},scale={}", i, scale);
            let ss = [
                (0, 0),
                (0, 1),
                (1, 1),
                (1, 0),
                (1, 0),
                (1, 1),
                (0, 1),
                (0, 0),
            ];
            let mut k = 0;
            while k < 1 << n {
                for t in 0..8 {
                    if k >= 1 << n {
                        break;
                    }
                    for _ in 0..scale {
                        if i % 2 == 0 {
                            xs[k] |= ss[t].1 << i;
                        }
                        if i % 2 == 1 {
                            xs[k] |= ss[t].0 << i;
                        }
                        k += 1;
                    }
                }
            }
            if a & (1 << i) != b & (1 << i) {
                let rs = [
                    (0, 0),
                    (0, 1),
                    (1, 1),
                    (1, 0),
                    (1, 0),
                    (0, 0),
                    (0, 1),
                    (1, 1),
                ];
                let mut k = ((1 << n) - scale * 8) as usize;
                for t in 0..8 {
                    for _ in 0..scale {
                        if i % 2 == 0 {
                            xs[k] = (xs[k] & !(1 << i)) | (rs[t].1 << i);
                        }
                        if i % 2 == 1 {
                            xs[k] = (xs[k] & !(1 << i)) | (rs[t].0 << i);
                        }
                        k += 1;
                    }
                }
                assert!(k == 1 << n);
            }
        }
        for k in 1 << (n - 1)..1 << n {
            xs[k] |= 1 << (n - 1);
        }
        for k in 0..1 << n {
            // eprintln!("{:06b}", xs[k]);
        }
        let mut res = vec![];
        for &r in &xs {
            res.push(swap_bit(a, flip1, flip2) ^ swap_bit(r, flip1, flip2));
        }
        writeln!(buf, "YES");
        write!(buf, "{}", res[0]);
        for &r in res.iter().skip(1) {
            write!(buf, " {}", r);
        }
        writeln!(buf, "");
    } else {
        writeln!(buf, "NO");
    }
    buf
}