Day 9 - part 2

This commit is contained in:
JonOfUs 2022-12-10 13:33:11 +01:00
parent d63a8d37e5
commit 168479c5b1

View file

@ -1,9 +1,9 @@
use std::fs;
const GRID_WIDTH: u32 = 1000;
const GRID_HEIGHT: u32 = 1000;
const START_X: u32 = 500;
const START_Y: u32 = 500;
const GRID_WIDTH: i32 = 1000;
const GRID_HEIGHT: i32 = 1000;
const START_X: i32 = 500;
const START_Y: i32 = 500;
pub fn solve() {
@ -32,7 +32,7 @@ pub fn solve() {
"R" => Dir::Right,
_ => Dir::Up
};
let amount = cmd[1].parse::<u32>().unwrap();
let amount = cmd[1].parse::<i32>().unwrap();
// move head
for _ in 0..amount {
@ -62,13 +62,13 @@ enum Dir {
}
struct Rope {
knots_x: Vec<u32>,
knots_y: Vec<u32>,
knots_x: Vec<i32>,
knots_y: Vec<i32>,
tail_visited_grid: Vec<Vec<bool>> // [Y][X]
}
impl Rope {
pub fn new(knots: u32) -> Self {
pub fn new(knots: i32) -> Self {
Rope {
knots_x: (0..knots).map(|_| START_X).collect(),
knots_y: (0..knots).map(|_| START_Y).collect(),
@ -102,67 +102,51 @@ impl Rope {
fn check_tail_pos(&mut self) {
// check pos of each knot except first
for i in 1..self.knots_x.len() {
// head is too far top/bottom
if self.knots_x[i-1].abs_diff(self.knots_x[i]) > 1 {
// if necessary, move on Y-axis
self.knots_y[i] = self.knots_y[i-1];
if self.knots_x[i-1] > self.knots_x[i] { // head below
self.knots_x[i] = self.knots_x[i-1]-1;
} else { // head above
self.knots_x[i] = self.knots_x[i-1]+1;
}
}
// head is too far left/right
else if self.knots_y[i-1].abs_diff(self.knots_y[i]) > 1 {
// if necessary, move on X-axis
self.knots_x[i] = self.knots_x[i-1];
if self.knots_y[i-1] > self.knots_y[i] { // head right
self.knots_y[i] = self.knots_y[i-1]-1;
} else { // head left
self.knots_y[i] = self.knots_y[i-1]+1;
if (self.knots_x[i-1] == self.knots_x[i] && (self.knots_y[i-1] - self.knots_y[i]).abs() == 1)
|| (self.knots_y[i-1] == self.knots_y[i] && (self.knots_x[i-1] - self.knots_x[i]).abs() == 1) {
// Knots are touching, nothing to do
} else if (self.knots_x[i-1] - self.knots_x[i]).abs() == 1 && (self.knots_y[i-1] - self.knots_y[i]).abs() == 1 {
// Knots are touching diagonally, nothing to do
} else {
// Tail needs to be moved
if self.knots_x[i-1] != self.knots_x[i] && self.knots_y[i-1] != self.knots_y[i] {
// Move diagonally
self.knots_x[i] += normalize(self.knots_x[i-1] - self.knots_x[i]);
self.knots_y[i] += normalize(self.knots_y[i-1] - self.knots_y[i]);
} else {
// Move vertically/horizontally
if self.knots_x[i-1] == self.knots_x[i] {
self.knots_y[i] += normalize(self.knots_y[i-1] - self.knots_y[i]);
} else {
self.knots_x[i] += normalize(self.knots_x[i-1] - self.knots_x[i]);
}
}
}
}
// set current tail (last knot) pos as visited
self.tail_visited_grid[*self.knots_y.last().unwrap() as usize][*self.knots_x.last().unwrap() as usize] = true;
/*
let min_x = self.knots_x.iter().min().unwrap();
let max_x = self.knots_x.iter().max().unwrap();
let min_y = self.knots_y.iter().min().unwrap();
let max_y = self.knots_y.iter().max().unwrap();
let width = max_x - min_x + 1;
let height = max_y - min_y + 1;
let mut out: Vec<Vec<String>> = (0..height).map(|_| (0..width).map(|_| ".".to_string()).collect()).collect();
for i in (0..self.knots_x.len()).rev() {
let x = self.knots_x[i]-min_x;
let y = self.knots_y[i]-min_y;
out[y as usize][x as usize] = i.to_string();
}
println!("{}", min_y);
out.iter().for_each(|line| {
line.iter().for_each(|o| print!("{}",o));
println!();
});
println!();*/
// Set current tail (last knot) pos as visited
self.tail_visited_grid[*self.knots_y.last().unwrap() as usize][*self.knots_x.last().unwrap() as usize] = true;
}
// returns number of cells visited by tail
pub fn tail_visited_num(&self) -> u32 {
pub fn tail_visited_num(&self) -> i32 {
self.tail_visited_grid.iter()
.map(|row|
row.iter()
.map(|cell|
if *cell { 1 as u32 }
else { 0 as u32 }
).sum::<u32>()
if *cell { 1 as i32 }
else { 0 as i32 }
).sum::<i32>()
).sum()
}
}
fn normalize(n: i32) -> i32 {
if n > 0 {
1
} else if n < 0 {
-1
} else {
0
}
}