Problem:
Score : 200 points

Problem Statement

There is a square in the xy-plane. The coordinates of its four vertices are (x_1,y_1),(x_2,y_2),(x_3,y_3) and (x_4,y_4) in counter-clockwise order.
(Assume that the positive x-axis points right, and the positive y-axis points up.)

Takahashi remembers (x_1,y_1) and (x_2,y_2), but he has forgot (x_3,y_3) and (x_4,y_4).

Given x_1,x_2,y_1,y_2, restore x_3,y_3,x_4,y_4. It can be shown that x_3,y_3,x_4 and y_4 uniquely exist and have integer values.

Constraints

|x_1|,|y_1|,|x_2|,|y_2| \leq 100

(x_1,y_1) ≠ (x_2,y_2)

All values in input are integers.

Input

Input is given from Standard Input in the following format:

x_1 y_1 x_2 y_2

Output

Print x_3,y_3,x_4 and y_4 as integers, in this order.

Sample Input 1

0 0 0 1

Sample Output 1

-1 1 -1 0

(0,0),(0,1),(-1,1),(-1,0) is the four vertices of a square in counter-clockwise order.
Note that (x_3,y_3)=(1,1),(x_4,y_4)=(1,0) is not accepted, as the vertices are in clockwise order.

Sample Input 2

2 3 6 6

Sample Output 2

3 10 -1 7

Sample Input 3

31 -41 -59 26

Sample Output 3

-126 -64 -36 -131

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

pub trait FromFragments: Sized {
    fn fragments_count() -> usize;
    fn from_fragments(fragments: &[&str]) -> Result<Self, String>;
}
impl FromFragments for String {
    fn fragments_count() -> usize {
        1
    }
    fn from_fragments(fragments: &[&str]) -> Result<String, String> {
        Ok(fragments[0].to_string())
    }
}
macro_rules ! impl_from_fragments { ( $ ( $ t : ty ) * ) => { $ ( impl FromFragments for $ t { fn fragments_count ( ) -> usize { 1 } fn from_fragments ( fragments : & [ & str ] ) -> Result <$ t , String > { use std :: str :: FromStr ; <$ t >:: from_str ( fragments [ 0 ] ) . map_err ( | _ | { format ! ( "cannot parse \"{}\" as {}" , fragments [ 0 ] , stringify ! ( $ t ) ) } ) } } ) * } ; }
impl_from_fragments ! ( isize usize i8 u8 i16 u16 i32 u32 i64 u64 f32 f64 ) ;
pub trait FromLine: Sized {
    fn from_line(line: &str) -> Result<Self, String>;
}
fn split_into_fragments(line: &str) -> Vec<&str> {
    line.trim_right_matches('\n').split_whitespace().collect()
}
impl<T: FromFragments> FromLine for T {
    fn from_line(line: &str) -> Result<T, String> {
        let fragments = split_into_fragments(line);
        if fragments.len() != T::fragments_count() {
            return Err(format!(
                "line \"{}\" has {} fragments, expected {}",
                line,
                fragments.len(),
                T::fragments_count()
            ));
        }
        T::from_fragments(&fragments)
    }
}
impl<T: FromFragments> FromLine for Vec<T> {
    fn from_line(line: &str) -> Result<Vec<T>, String> {
        let n = T::fragments_count();
        let fragments = split_into_fragments(line);
        if fragments.len() % n != 0 {
            return Err(format!(
                "line \"{}\" has {} fragments, expected multiple of {}",
                line,
                fragments.len(),
                n
            ));
        }
        let mut result = Vec::new();
        for chunk in fragments.chunks(n) {
            match T::from_fragments(chunk) {
                Ok(v) => result.push(v),
                Err(msg) => {
                    let flagment_msg = if n == 1 {
                        format!("fragment {}", result.len())
                    } else {
                        let l = result.len();
                        format!("fragments {}-{}", n * l + 1, (n + 1) * l)
                    };
                    return Err(format!("{} of line \"{}\": {}", flagment_msg, line, msg));
                }
            }
        }
        Ok(result)
    }
}
macro_rules ! impl_from_fragments_for_tuples { ( $ t : ident $ var : ident $ count : expr ) => ( ) ; ( $ t : ident $ var : ident $ count : expr ; $ ( $ inner_t : ident $ inner_var : ident $ inner_count : expr ) ;* ) => { impl_from_fragments_for_tuples ! ( $ ( $ inner_t $ inner_var $ inner_count ) ;* ) ; impl <$ t : FromFragments , $ ( $ inner_t : FromFragments ) ,*> FromFragments for ( $ t , $ ( $ inner_t ) ,* ) { fn fragments_count ( ) -> usize { let mut n = <$ t >:: fragments_count ( ) ; $ ( n += <$ inner_t >:: fragments_count ( ) ; ) * n } # [ allow ( unused_assignments ) ] fn from_fragments ( fragments : & [ & str ] ) -> Result < ( $ t , $ ( $ inner_t ) ,* ) , String > { let mut start = 0 ; let $ var = <$ t >:: from_fragments ( & fragments [ start .. start +<$ t >:: fragments_count ( ) ] ) ?; start += <$ t >:: fragments_count ( ) ; $ ( let $ inner_var = <$ inner_t >:: from_fragments ( & fragments [ start .. start +<$ inner_t >:: fragments_count ( ) ] ) ?; start += <$ inner_t >:: fragments_count ( ) ; ) * Ok ( ( $ var , $ ( $ inner_var ) ,* ) ) } } } }
impl_from_fragments_for_tuples ! ( T4 x4 4 ; T3 x3 3 ; T2 x2 2 ; T1 x1 1 ) ;
#[macro_export]
macro_rules ! read { ( ) => { let mut line = String :: new ( ) ; std :: io :: stdin ( ) . read_line ( & mut line ) . unwrap ( ) ; } ; ( $ pat : pat = $ t : ty ) => { let mut line = String :: new ( ) ; std :: io :: stdin ( ) . read_line ( & mut line ) . unwrap ( ) ; let $ pat = <$ t >:: from_line ( & line ) . unwrap ( ) ; } ; ( $ ( $ pat : pat = $ t : ty ) ,+ ) => { read ! ( ( $ ( $ pat ) ,* ) = ( $ ( $ t ) ,* ) ) ; } ; }
#[macro_export]
macro_rules ! readls { ( $ ( $ pat : pat = $ t : ty ) ,+ ) => { $ ( read ! ( $ pat = $ t ) ; ) * } }
#[macro_export]
macro_rules ! read_loop { ( $ pat : pat = $ t : ty ; $ block : block ) => { use std :: io :: BufRead ; let stdin = std :: io :: stdin ( ) ; for line in stdin . lock ( ) . lines ( ) { let line = line . expect ( "read from stdin failed" ) ; let $ pat = <$ t >:: from_line ( & line ) . unwrap ( ) ; $ block } } ; ( $ ( $ pat : pat = $ t : ty ) ,* ; $ block : block ) => { read_loop ! ( ( $ ( $ pat ) ,* ) = ( $ ( $ t ) ,* ) ; $ block ) ; } }
#[macro_export]
macro_rules ! readn_loop { ( $ n : expr ; $ pat : pat = $ t : ty ; $ block : block ) => { use std :: io :: BufRead ; let stdin = std :: io :: stdin ( ) ; { let lock = stdin . lock ( ) ; for _ in 0 ..$ n { let line = String :: new ( ) ; lock . read_line ( & mut line ) . expect ( "read from stdin failed" ) ; let $ pat = <$ t >:: from_line ( & line ) . unwrap ( ) ; $ block } } } ; ( $ n : expr ; $ ( $ pat : pat = $ t : ty ) ,* ; $ block : block ) => { read_times_loop ! ( $ n ; ( $ ( $ pat ) ,* ) = ( $ ( $ t ) ,* ) ; $ block ) ; } }

use std::fmt::{self, Display, Formatter};
use std::ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Neg, Sub, SubAssign};
#[derive(Clone, Copy, Debug, PartialEq)]
pub struct Vec2<T> {
    pub x: T,
    pub y: T,
}
impl<T> Vec2<T> {
    pub fn new(x: T, y: T) -> Vec2<T> {
        Vec2 { x: x, y: y }
    }
}
impl<T: Display> Display for Vec2<T> {
    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
        write!(f, "{} {}", self.x, self.y)
    }
}
impl<S, T: Add<S>> Add<Vec2<S>> for Vec2<T> {
    type Output = Vec2<T::Output>;
    fn add(self, rhs: Vec2<S>) -> Self::Output {
        Vec2::new(self.x + rhs.x, self.y + rhs.y)
    }
}
impl<S, T: AddAssign<S>> AddAssign<Vec2<S>> for Vec2<T> {
    fn add_assign(&mut self, rhs: Vec2<S>) {
        self.x += rhs.x;
        self.y += rhs.y;
    }
}
impl<S, T: Sub<S>> Sub<Vec2<S>> for Vec2<T> {
    type Output = Vec2<T::Output>;
    fn sub(self, rhs: Vec2<S>) -> Self::Output {
        Vec2::new(self.x - rhs.x, self.y - rhs.y)
    }
}
impl<S, T: SubAssign<S>> SubAssign<Vec2<S>> for Vec2<T> {
    fn sub_assign(&mut self, rhs: Vec2<S>) {
        self.x -= rhs.x;
        self.y -= rhs.y;
    }
}
impl<T: Neg> Neg for Vec2<T> {
    type Output = Vec2<T::Output>;
    fn neg(self) -> Self::Output {
        Vec2::new(-self.x, -self.y)
    }
}
macro_rules ! impl_mul_vec2 { ( $ ( $ t : ty ) * ) => { $ ( impl Mul < Vec2 <$ t >> for $ t { type Output = Vec2 <<$ t as Mul >:: Output >; fn mul ( self , rhs : Vec2 <$ t > ) -> Self :: Output { Vec2 :: new ( self * rhs . x , self * rhs . y ) } } ) * } }
impl_mul_vec2 ! ( i8 u8 i16 u16 i32 u32 i64 u64 f32 f64 ) ;
impl<S: Copy, T: Mul<S>> Mul<S> for Vec2<T> {
    type Output = Vec2<T::Output>;
    fn mul(self, rhs: S) -> Self::Output {
        Vec2::new(self.x * rhs, self.y * rhs)
    }
}
impl<S: Copy, T: MulAssign<S>> MulAssign<S> for Vec2<T> {
    fn mul_assign(&mut self, rhs: S) {
        self.x *= rhs;
        self.y *= rhs;
    }
}
impl<S: Copy, T: Div<S>> Div<S> for Vec2<T> {
    type Output = Vec2<T::Output>;
    fn div(self, rhs: S) -> Self::Output {
        Vec2::new(self.x / rhs, self.y / rhs)
    }
}
impl<S: Copy, T: DivAssign<S>> DivAssign<S> for Vec2<T> {
    fn div_assign(&mut self, rhs: S) {
        self.x /= rhs;
        self.y /= rhs;
    }
}
impl<T: FromFragments> FromFragments for Vec2<T> {
    fn fragments_count() -> usize {
        T::fragments_count() * 2
    }
    fn from_fragments(fragments: &[&str]) -> Result<Vec2<T>, String> {
        let n = T::fragments_count();
        Ok(Vec2::new(
            T::from_fragments(&fragments[..n])?,
            T::from_fragments(&fragments[n..])?,
        ))
    }
}

fn main() {
    read!(p1 = Vec2<i16>, p2 = Vec2<i16>);
    let delta = p2 - p1;
    let delta_rot = Vec2::new(-delta.y, delta.x);

    println!("{} {}", p2 + delta_rot, p1 + delta_rot);
}