Problem:
Score: 100 points

Problem Statement

A triple of numbers is said to be poor when two of those numbers are equal but the other number is different from those two numbers.

You will be given three integers A, B, and C. If this triple is poor, print Yes; otherwise, print No.

Constraints

A, B, and C are all integers between 1 and 9 (inclusive).

Input

Input is given from Standard Input in the following format:

A B C

Output

If the given triple is poor, print Yes; otherwise, print No.

Sample Input 1

5 7 5

Sample Output 1

Yes

A and C are equal, but B is different from those two numbers, so this triple is poor.

Sample Input 2

4 4 4

Sample Output 2

No

A, B, and C are all equal, so this triple is not poor.

Sample Input 3

4 9 6

Sample Output 3

No

Sample Input 4

3 3 4

Sample Output 4

Yes

Solution in Rust (1.15.1) (judge verdict: Accepted)

use std::io;
use std::cmp;
use io_ext::Reader;
use parse::ParseAll;
use int_ext::{combination, digits10};

fn main() {
    let stdin = io::stdin();
    let mut r = Reader::new(stdin.lock());
    let (a, b, c): (i64, i64, i64) = r.read_line().split_whitespace().parse_all();
    let s = if a == b {
        if b == c {
            "No"
        } else {
            "Yes"
        }
    } else {
        if a == c || b == c {
            "Yes"
        } else {
            "No"
        }
    };
    println!("{}", s);
}

#[cfg(test)]
mod tests {
    use super::answer;

    #[test]
    fn test() {
        let digits = [1, 0, 0];
        let k = 1;
        assert_eq!(answer(&digits, k), 19);

        let digits = [2, 5];
        let k = 2;
        assert_eq!(answer(&digits, k), 14);

        let digits = [3, 1, 4, 1, 5, 9];
        let k = 2;
        assert_eq!(answer(&digits, k), 937);

        let digits: Vec<u8> = (0..100).map(|_| 9).collect();
        let k = 3;
        assert_eq!(answer(&digits, k), 117879300);
    }
}

pub mod int_ext {
    pub fn digits10(n: i64) -> i64 {
        assert!(n >= 0);

        let mut d = 1;
        let mut p = 10;
        while p <= n {
            p *= 10;
            d += 1;
        }
        d
    }

    pub fn permutation(n: i64, k: i64) -> i64 {
        assert!(k >= 0);
        assert!(n >= k);

        let mut p = 1;
        for i in 0..k {
            p = p * (n - i);
        }
        p
    }

    pub fn combination(n: i64, k: i64) -> i64 {
        use std::cmp;

        assert!(k >= 0);
        assert!(n >= k);

        let k = cmp::min(k, n - k);
        let num = permutation(n, k);
        let mut den = 1;
        for i in 0..k {
            den = den * (i + 1);
        }
        num / den
    }
}

/// A module for easy use of io.
pub mod io_ext {
    use std::io::BufRead;

    pub struct Reader<R> {
        buf: String,
        inner: R,
    }

    impl<R> Reader<R> {
        #[inline]
        pub fn new(inner: R) -> Self {
            Reader { buf: String::new(), inner: inner }
        }

        #[inline]
        pub fn into_inner(self) -> R {
            self.inner
        }
    }

    impl<R: BufRead> Reader<R> {
        #[allow(deprecated)]
        #[inline]
        pub fn read_line(&mut self) -> &str {
            self.buf.clear();
            self.inner.read_line(&mut self.buf).unwrap_or_else(|e| panic!("{}", e));
            self.buf.trim_right()
        }
    }
}

/// Parsing Iterator.
pub mod parse {
    use std::borrow::Borrow;
    use std::str::FromStr;

    pub trait FromStrIterator {
        fn from_str_iter<S: Borrow<str>, I: Iterator<Item=S>>(i: I) -> Self;
    }

    pub trait ParseAll {
        fn parse_all<F: FromStrIterator>(self) -> F;
    }

    impl<S: Borrow<str>, I: Iterator<Item=S>> ParseAll for I {
        #[inline]
        fn parse_all<F: FromStrIterator>(self) -> F {
            F::from_str_iter(self)
        }
    }

    fn parse<S: Borrow<str>, I: Iterator<Item=S>, F: FromStr>(i: &mut I) -> F {
        i.next().unwrap_or_else(|| panic!("too few strings error")).borrow().parse().unwrap_or_else(|_| panic!("parse error"))
    }

    // To avoid conflict, this is not implemented for `A` but `(A,)`.
    impl<A: FromStr> FromStrIterator for (A, ) {
        fn from_str_iter<S: Borrow<str>, I: Iterator<Item=S>>(mut i: I) -> Self {
            let a = parse(&mut i);
            if i.next().is_some() {
                panic!("too many strings error");
            }
            (a, )
        }
    }

    impl<A: FromStr, B: FromStr> FromStrIterator for (A, B) {
        fn from_str_iter<S: Borrow<str>, I: Iterator<Item=S>>(mut i: I) -> Self {
            let a = parse(&mut i);
            let b = parse(&mut i);
            if i.next().is_some() {
                panic!("too many strings error");
            }
            (a, b)
        }
    }

    impl<A: FromStr, B: FromStr, C: FromStr> FromStrIterator for (A, B, C) {
        fn from_str_iter<S: Borrow<str>, I: Iterator<Item=S>>(mut i: I) -> Self {
            let a = parse(&mut i);
            let b = parse(&mut i);
            let c = parse(&mut i);
            if i.next().is_some() {
                panic!("too many strings error");
            }
            (a, b, c)
        }
    }

    impl<A: FromStr, B: FromStr, C: FromStr, D: FromStr> FromStrIterator for (A, B, C, D) {
        fn from_str_iter<S: Borrow<str>, I: Iterator<Item=S>>(mut i: I) -> Self {
            let a = parse(&mut i);
            let b = parse(&mut i);
            let c = parse(&mut i);
            let d = parse(&mut i);
            if i.next().is_some() {
                panic!("too many strings error");
            }
            (a, b, c, d)
        }
    }

    impl<T: FromStr> FromStrIterator for Vec<T> {
        fn from_str_iter<S: Borrow<str>, I: Iterator<Item=S>>(i: I) -> Self {
            i.map(|s| s.borrow().parse().unwrap_or_else(|_| panic!("parse error"))).collect()
        }
    }
}

pub mod modulo {
    /// Returns `x` + `y` mod `modulo`.
    ///
    /// `x < modulo` and `y < modulo` must hold.
    #[inline]
    pub fn add(x: u32, y: u32, modulo: u32) -> u32 {
        debug_assert!(modulo > 0);
        debug_assert!(x < modulo && y < modulo);
        let sum = x as u64 + y as u64;
        if sum <= modulo as u64 {
            sum as u32
        } else {
            (sum as u32).wrapping_sub(modulo)
        }
    }

    /// Returns `x` - `y` mod `modulo`.
    ///
    /// `x < modulo` and `y < modulo` must hold.
    #[inline]
    pub fn sub(x: u32, y: u32, modulo: u32) -> u32 {
        debug_assert!(0 < modulo);
        debug_assert!(x < modulo && y < modulo);
        if x >= y {
            x - y
        } else {
            modulo + x - y
        }
    }

    /// Returns `x` * `y` mod `modulo`.
    #[inline]
    pub fn mul(x: u32, y: u32, modulo: u32) -> u32 {
        ((x as u64 * y as u64) % modulo as u64) as u32
    }

    /// Returns `x`^ `y` mod `modulo`.
    pub fn pow(x: u32, mut y: u32, modulo: u32) -> u32 {
        debug_assert!(0 < modulo);
        let mut p = x;
        let mut ret = 1;

        while y != 0 {
            if y & 1 == 1 {
                ret = mul(ret, p, modulo);
            }
            p = mul(p, p, modulo);
            y >>= 1;
        }
        ret
    }

    fn is_prime(x: u32) -> bool {
        let sqrt = (x as f32).sqrt() as u32;
        for factor in 2..sqrt {
            if x % factor == 0 {
                return false;
            }
        }
        true
    }

    /// Returns 1 / `x`.
    ///
    /// `modulo` must be a prime number.
    #[inline]
    fn reciprocal(x: u32, modulo: u32) -> u32 {
        debug_assert!(0 < modulo && is_prime(modulo));
        pow(x, modulo - 2, modulo)
    }

    /// Returns `x` / `y` mod `modulo`.
    ///
    /// `modulo` must be a prime number.
    #[inline]
    pub fn div(x: u32, y: u32, modulo: u32) -> u32 {
        debug_assert!(0 < modulo && is_prime(modulo));
        mul(x, reciprocal(y, modulo), modulo)
    }

    /// Returns `n`P`k` mod `modulo`.
    pub fn perm(n: u32, k: u32, modulo: u32) -> u32 {
        let mut p = 1;
        for i in 0..k {
            p = mul(p, n - i, modulo);
        }
        p
    }

    /// Returns `n`C`k` mod `modulo`.
    pub fn comb(n: u32, k: u32, modulo: u32) -> u32 {
        let num = perm(n, k, modulo);
        let mut den = 1;
        for i in 0..k {
            den = mul(den, i + 1, modulo);
        }
        div(num, den, modulo)
    }
}