1use std::{
  2    cmp::Ordering,
  3    ops::{Add, AddAssign, Sub},
  4};
  5
  6#[derive(Clone, Copy, Default, Eq, PartialEq, Debug, Hash)]
  7pub struct Point {
  8    pub row: u32,
  9    pub column: u32,
 10}
 11
 12impl Point {
 13    pub const MAX: Self = Self {
 14        row: u32::MAX,
 15        column: u32::MAX,
 16    };
 17
 18    pub fn new(row: u32, column: u32) -> Self {
 19        Point { row, column }
 20    }
 21
 22    pub fn zero() -> Self {
 23        Point::new(0, 0)
 24    }
 25
 26    pub fn from_str(s: &str) -> Self {
 27        let mut point = Self::zero();
 28        for (row, line) in s.split('\n').enumerate() {
 29            point.row = row as u32;
 30            point.column = line.len() as u32;
 31        }
 32        point
 33    }
 34
 35    pub fn is_zero(&self) -> bool {
 36        self.row == 0 && self.column == 0
 37    }
 38}
 39
 40impl<'a> Add<&'a Self> for Point {
 41    type Output = Point;
 42
 43    fn add(self, other: &'a Self) -> Self::Output {
 44        self + *other
 45    }
 46}
 47
 48impl Add for Point {
 49    type Output = Point;
 50
 51    fn add(self, other: Self) -> Self::Output {
 52        if other.row == 0 {
 53            Point::new(self.row, self.column + other.column)
 54        } else {
 55            Point::new(self.row + other.row, other.column)
 56        }
 57    }
 58}
 59
 60impl<'a> Sub<&'a Self> for Point {
 61    type Output = Point;
 62
 63    fn sub(self, other: &'a Self) -> Self::Output {
 64        self - *other
 65    }
 66}
 67
 68impl Sub for Point {
 69    type Output = Point;
 70
 71    fn sub(self, other: Self) -> Self::Output {
 72        debug_assert!(other <= self);
 73
 74        if self.row == other.row {
 75            Point::new(0, self.column - other.column)
 76        } else {
 77            Point::new(self.row - other.row, self.column)
 78        }
 79    }
 80}
 81
 82impl<'a> AddAssign<&'a Self> for Point {
 83    fn add_assign(&mut self, other: &'a Self) {
 84        *self += *other;
 85    }
 86}
 87
 88impl AddAssign<Self> for Point {
 89    fn add_assign(&mut self, other: Self) {
 90        if other.row == 0 {
 91            self.column += other.column;
 92        } else {
 93            self.row += other.row;
 94            self.column = other.column;
 95        }
 96    }
 97}
 98
 99impl PartialOrd for Point {
100    fn partial_cmp(&self, other: &Point) -> Option<Ordering> {
101        Some(self.cmp(other))
102    }
103}
104
105impl Ord for Point {
106    #[cfg(target_pointer_width = "64")]
107    fn cmp(&self, other: &Point) -> Ordering {
108        let a = (self.row as usize) << 32 | self.column as usize;
109        let b = (other.row as usize) << 32 | other.column as usize;
110        a.cmp(&b)
111    }
112
113    #[cfg(target_pointer_width = "32")]
114    fn cmp(&self, other: &Point) -> Ordering {
115        match self.row.cmp(&other.row) {
116            Ordering::Equal => self.column.cmp(&other.column),
117            comparison @ _ => comparison,
118        }
119    }
120}