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 is_zero(&self) -> bool {
 27        self.row == 0 && self.column == 0
 28    }
 29}
 30
 31impl<'a> Add<&'a Self> for Point {
 32    type Output = Point;
 33
 34    fn add(self, other: &'a Self) -> Self::Output {
 35        self + *other
 36    }
 37}
 38
 39impl Add for Point {
 40    type Output = Point;
 41
 42    fn add(self, other: Self) -> Self::Output {
 43        if other.row == 0 {
 44            Point::new(self.row, self.column + other.column)
 45        } else {
 46            Point::new(self.row + other.row, other.column)
 47        }
 48    }
 49}
 50
 51impl<'a> Sub<&'a Self> for Point {
 52    type Output = Point;
 53
 54    fn sub(self, other: &'a Self) -> Self::Output {
 55        self - *other
 56    }
 57}
 58
 59impl Sub for Point {
 60    type Output = Point;
 61
 62    fn sub(self, other: Self) -> Self::Output {
 63        debug_assert!(other <= self);
 64
 65        if self.row == other.row {
 66            Point::new(0, self.column - other.column)
 67        } else {
 68            Point::new(self.row - other.row, self.column)
 69        }
 70    }
 71}
 72
 73impl<'a> AddAssign<&'a Self> for Point {
 74    fn add_assign(&mut self, other: &'a Self) {
 75        *self += *other;
 76    }
 77}
 78
 79impl AddAssign<Self> for Point {
 80    fn add_assign(&mut self, other: Self) {
 81        if other.row == 0 {
 82            self.column += other.column;
 83        } else {
 84            self.row += other.row;
 85            self.column = other.column;
 86        }
 87    }
 88}
 89
 90impl PartialOrd for Point {
 91    fn partial_cmp(&self, other: &Point) -> Option<Ordering> {
 92        Some(self.cmp(other))
 93    }
 94}
 95
 96impl Ord for Point {
 97    #[cfg(target_pointer_width = "64")]
 98    fn cmp(&self, other: &Point) -> Ordering {
 99        let a = (self.row as usize) << 32 | self.column as usize;
100        let b = (other.row as usize) << 32 | other.column as usize;
101        a.cmp(&b)
102    }
103
104    #[cfg(target_pointer_width = "32")]
105    fn cmp(&self, other: &Point) -> Ordering {
106        match self.row.cmp(&other.row) {
107            Ordering::Equal => self.column.cmp(&other.column),
108            comparison @ _ => comparison,
109        }
110    }
111}