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use advent_lib::prelude::*;
use std::collections::HashMap;
fn main() -> Result<()> {
let mut args = std::env::args();
if args.len() != 2 {
eprintln!("Usage: advent input");
}
let _ = args.next();
let filename = args.next().unwrap();
let input = advent_lib::read_lines_file(&filename)?;
let mut line_specs = Vec::new();
for line in &input {
let words: Vec<&str> = line.split_whitespace().collect();
let start = parse_coords(words[0])?;
let end = parse_coords(words[2])?;
line_specs.push((start, end));
}
{
let mut counts: HashMap<(i64, i64), i64> = HashMap::new();
for ((x_start, y_start), (x_end, y_end)) in &line_specs {
if x_start == x_end {
let x = *x_start;
let (y_min, y_max) = if y_start <= y_end {
(y_start, y_end)
} else {
(y_end, y_start)
};
for y in *y_min .. y_max + 1 {
let n = match counts.get(&(x, y)) {
Some(n) => *n,
None => 0,
};
counts.insert((x, y), n + 1);
}
} else if y_start == y_end {
let y = *y_start;
let (x_min, x_max) = if x_start <= x_end {
(x_start, x_end)
} else {
(x_end, x_start)
};
for x in *x_min .. x_max + 1 {
let n = match counts.get(&(x, y)) {
Some(n) => *n,
None => 0,
};
counts.insert((x, y), n + 1);
}
}
}
let mut n_intersections = 0;
for cell in counts.values() {
if *cell > 1 {
n_intersections += 1;
}
}
println!("{}", n_intersections);
}
{
let mut counts: HashMap<(i64, i64), i64> = HashMap::new();
for ((x_start, y_start), (x_end, y_end)) in &line_specs {
if x_start == x_end {
let x = *x_start;
let (y_min, y_max) = if y_start <= y_end {
(y_start, y_end)
} else {
(y_end, y_start)
};
for y in *y_min .. y_max + 1 {
let n = match counts.get(&(x, y)) {
Some(n) => *n,
None => 0,
};
counts.insert((x, y), n + 1);
}
} else if y_start == y_end {
let y = *y_start;
let (x_min, x_max) = if x_start <= x_end {
(x_start, x_end)
} else {
(x_end, x_start)
};
for x in *x_min .. x_max + 1 {
let n = match counts.get(&(x, y)) {
Some(n) => *n,
None => 0,
};
counts.insert((x, y), n + 1);
}
} else {
let (x_start, x_end, y_start, y_end) = if x_start <= x_end {
(x_start, x_end, y_start, y_end)
} else {
(x_end, x_start, y_end, y_start)
};
if y_start <= y_end {
for i in 0 .. x_end + 1 - x_start {
let x = x_start + i;
let y = y_start + i;
let n = match counts.get(&(x, y)) {
Some(n) => *n,
None => 0,
};
counts.insert((x, y), n + 1);
}
} else {
for i in 0 .. x_end + 1 - x_start {
let x = x_start + i;
let y = y_start - i;
let n = match counts.get(&(x, y)) {
Some(n) => *n,
None => 0,
};
counts.insert((x, y), n + 1);
}
}
}
}
let mut n_intersections = 0;
for cell in counts.values() {
if *cell > 1 {
n_intersections += 1;
}
}
println!("{}", n_intersections);
}
Ok(())
}
fn parse_coords(word: &str) -> Result<(i64, i64)> {
let values: Vec<&str> = word.split(',').collect();
let x = values[0].parse::<i64>()?;
let y = values[1].parse::<i64>()?;
Ok((x, y))
}
|