97 lines
3.1 KiB
Rust
97 lines
3.1 KiB
Rust
#![warn(clippy::all, clippy::pedantic)]
|
|
|
|
mod common;
|
|
use common::day_input;
|
|
|
|
#[derive(Debug)]
|
|
struct Vec2 { x: i64, y: i64 }
|
|
#[derive(Debug)]
|
|
struct Rect { top_left: Vec2, bottom_right: Vec2 }
|
|
|
|
fn parse_target_rect(s: &str) -> Rect {
|
|
let mut nums: Vec<Vec<i64>> =
|
|
s
|
|
.split(": ")
|
|
.nth(1).unwrap()
|
|
.split(", ")
|
|
.take(2)
|
|
.map(|s| s.split("=")
|
|
.nth(1).unwrap()
|
|
.split("..")
|
|
.map(|s2| {
|
|
// println!("Parsing Int: {}", s2);
|
|
s2.parse::<i64>().unwrap()
|
|
})
|
|
.take(2)
|
|
.collect()
|
|
).collect();
|
|
let mut xr: Vec<i64> = nums.remove(0);
|
|
let mut yr: Vec<i64> = nums.remove(0);
|
|
xr.sort();
|
|
yr.sort();
|
|
Rect { top_left: Vec2 { x: xr[0], y: yr[1] }, bottom_right: Vec2 { x: xr[1], y: yr[0] } }
|
|
}
|
|
|
|
fn simulate_shot(initial_vel: Vec2, target: &Rect) -> Result<(Vec2, i64), (Vec2, Vec2)> {
|
|
let mut vel = Vec2 { x: initial_vel.x, y: initial_vel.y };
|
|
let mut last_pos = Vec2 { x: 0, y: 0 };
|
|
let mut x: i64 = 0;
|
|
let mut y: i64 = 0;
|
|
let mut highest_y = y;
|
|
while x <= target.bottom_right.x && y >= target.bottom_right.y {
|
|
// println!("At {}, {} (lim: {}->{}, {}->{})", x, y, target.top_left.x, target.bottom_right.x, target.top_left.y, target.bottom_right.y);
|
|
if x >= target.top_left.x && y <= target.top_left.y && x <= target.bottom_right.x && y >= target.bottom_right.y {
|
|
// println!("Ding!: {}, {} (lim: {}->{}, {}->{})", x, y, target.top_left.x, target.bottom_right.x, target.top_left.y, target.bottom_right.y);
|
|
return Ok((Vec2 { x, y }, highest_y));
|
|
}
|
|
last_pos = Vec2 { x, y };
|
|
x += vel.x;
|
|
y += vel.y;
|
|
if vel.x != 0 {
|
|
if vel.x > 0 { vel.x -= 1; }
|
|
else { vel.x += 1; }
|
|
}
|
|
if y > highest_y { highest_y = y; }
|
|
vel.y -= 1
|
|
}
|
|
// println!("Too Far: {}, {} (lim: {}->{}, {}->{})", x, y, target.top_left.x, target.bottom_right.x, target.top_left.y, target.bottom_right.y);
|
|
Err((Vec2 { x, y }, last_pos))
|
|
}
|
|
|
|
fn trick_shot(r: &Rect) -> (Option<i64>, i64) {
|
|
let mut result = None;
|
|
let mut valid_shots = 0;
|
|
for x in 1..=r.bottom_right.x {
|
|
for y in r.bottom_right.y..=-r.bottom_right.y*2 {
|
|
// println!("Simulating {}, {}", x, y);
|
|
if let Ok((v, hy)) = simulate_shot(Vec2 { x, y }, r) {
|
|
valid_shots += 1;
|
|
if result.is_some() {
|
|
if hy > result.unwrap() {
|
|
// println!("!! New Highest Y: {} via {}, {}", hy, x, y);
|
|
result = Some(hy);
|
|
}
|
|
} else {
|
|
result = Some(hy);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
(result, valid_shots)
|
|
}
|
|
|
|
fn main() {
|
|
let r = parse_target_rect(&day_input(17).trim());
|
|
println!("Trick Shot Data: {:#?}", trick_shot(&r));
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use super::*;
|
|
|
|
#[test]
|
|
fn packet_op_result_examples() {
|
|
let tester = |s: &str| trick_shot(&parse_target_rect(s));
|
|
assert_eq!(tester("target area: x=20..30, y=-10..-5"), (Some(45), 112));
|
|
}
|
|
}
|