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advent-of-code-2023
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Day 17b done

This commit is contained in:
Drew Galbraith 2023-12-19 10:12:20 -08:00
parent 00979e49cf
commit 4e51c57775
2 changed files with 43 additions and 45 deletions
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85
src/day17.rs
View File

@ -1,6 +1,6 @@
use std::io;
fn find_min_heat_loss(board: &Vec<Vec<u64>>) -> u64 {
fn find_min_heat_loss(board: &Vec<Vec<u64>>, min_move: usize, max_move: usize) -> u64 {
let mut horiz_min: Vec<Vec<u64>> = Vec::new();
let mut vert_min: Vec<Vec<u64>> = Vec::new();
@ -19,29 +19,28 @@ fn find_min_heat_loss(board: &Vec<Vec<u64>>) -> u64 {
for r in 0..board.len() {
for c in 0..board[r].len() {
let prev = horiz_min[r][c];
// Check Backwards.
if c > 0 && vert_min[r][c - 1] != u64::MAX {
horiz_min[r][c] = horiz_min[r][c].min(vert_min[r][c - 1] + board[r][c - 1]);
}
if c > 1 && vert_min[r][c - 2] != u64::MAX {
horiz_min[r][c] =
horiz_min[r][c].min(vert_min[r][c - 2] + board[r][c - 1] + board[r][c - 2]);
}
if c > 2 && vert_min[r][c - 3] != u64::MAX {
horiz_min[r][c] = horiz_min[r][c]
.min(vert_min[r][c - 3] + board[r][c - 1] + board[r][c - 2] + board[r][c - 3]);
let mut sum_back = 0;
let mut m = 1;
while m <= max_move && c >= m {
sum_back += board[r][c - m];
if m >= min_move && vert_min[r][c - m] != u64::MAX {
horiz_min[r][c] = horiz_min[r][c].min(vert_min[r][c - m] + sum_back);
}
m += 1;
}
// Check Forwards.
if c < board[r].len() - 1 && vert_min[r][c + 1] != u64::MAX {
horiz_min[r][c] = horiz_min[r][c].min(vert_min[r][c + 1] + board[r][c + 1]);
}
if c < board[r].len() - 2 && vert_min[r][c + 2] != u64::MAX {
horiz_min[r][c] =
horiz_min[r][c].min(vert_min[r][c + 2] + board[r][c + 1] + board[r][c + 2]);
}
if c < board[r].len() - 3 && vert_min[r][c + 3] != u64::MAX {
horiz_min[r][c] = horiz_min[r][c]
.min(vert_min[r][c + 3] + board[r][c + 1] + board[r][c + 2] + board[r][c + 3]);
let mut sum_forwards = 0;
let mut m = 1;
while m <= max_move && c + m < board[r].len() {
sum_forwards += board[r][c + m];
if m >= min_move && vert_min[r][c + m] != u64::MAX {
horiz_min[r][c] = horiz_min[r][c].min(vert_min[r][c + m] + sum_forwards);
}
m += 1;
}
if horiz_min[r][c] != prev {
@ -54,30 +53,28 @@ fn find_min_heat_loss(board: &Vec<Vec<u64>>) -> u64 {
for r in 0..board.len() {
for c in 0..board[r].len() {
let prev = vert_min[r][c];
// Check Backwards
if r > 0 && horiz_min[r - 1][c] != u64::MAX {
vert_min[r][c] = vert_min[r][c].min(horiz_min[r - 1][c] + board[r - 1][c]);
}
if r > 1 && horiz_min[r - 2][c] != u64::MAX {
vert_min[r][c] =
vert_min[r][c].min(horiz_min[r - 2][c] + board[r - 1][c] + board[r - 2][c]);
}
if r > 2 && horiz_min[r - 3][c] != u64::MAX {
vert_min[r][c] = vert_min[r][c]
.min(horiz_min[r - 3][c] + board[r - 1][c] + board[r - 2][c] + board[r - 3][c]);
// Check Backwards.
let mut sum_back = 0;
let mut m = 1;
while m <= max_move && r >= m {
sum_back += board[r - m][c];
if m >= min_move && horiz_min[r - m][c] != u64::MAX {
vert_min[r][c] = vert_min[r][c].min(horiz_min[r - m][c] + sum_back);
}
m += 1;
}
// Check Forwards.
if r < board.len() - 1 && horiz_min[r + 1][c] != u64::MAX {
vert_min[r][c] = vert_min[r][c].min(horiz_min[r + 1][c] + board[r + 1][c]);
}
if r < board.len() - 2 && horiz_min[r + 2][c] != u64::MAX {
vert_min[r][c] =
vert_min[r][c].min(horiz_min[r + 2][c] + board[r + 1][c] + board[r + 2][c]);
}
if r < board.len() - 3 && horiz_min[r + 3][c] != u64::MAX {
vert_min[r][c] = vert_min[r][c]
.min(horiz_min[r + 3][c] + board[r + 1][c] + board[r + 2][c] + board[r + 3][c]);
let mut sum_forwards = 0;
let mut m = 1;
while m <= max_move && r + m < board.len() {
sum_forwards += board[r + m][c];
if m >= min_move && horiz_min[r + m][c] != u64::MAX {
vert_min[r][c] = vert_min[r][c].min(horiz_min[r + m][c] + sum_forwards);
}
m += 1;
}
if vert_min[r][c] != prev {
@ -94,7 +91,7 @@ fn find_min_heat_loss(board: &Vec<Vec<u64>>) -> u64 {
horiz_min[0][0].min(vert_min[0][0])
}
pub fn min_heat_loss() -> u64 {
pub fn min_heat_loss(min_move: usize, max_move: usize) -> u64 {
let mut buffer = String::new();
while io::stdin().read_line(&mut buffer).unwrap() > 0 {}
@ -105,5 +102,5 @@ pub fn min_heat_loss() -> u64 {
.map(|s| s.chars().map(|c| (c as u64 - '0' as u64)).collect())
.collect();
find_min_heat_loss(&board)
find_min_heat_loss(&board, min_move, max_move)
}

3
src/main.rs
View File

@ -57,7 +57,8 @@ fn main() {
"day15b" => println!("Sum: {}", day15::hash_map()),
"day16a" => println!("Answer: {}", day16::solve()),
"day16b" => println!("Answer: {}", day16::find_best()),
"day17a" => println!("Minimum: {}", day17::min_heat_loss()),
"day17a" => println!("Minimum: {}", day17::min_heat_loss(1, 3)),
"day17b" => println!("Minimum: {}", day17::min_heat_loss(4, 10)),
_ => println!("Unrecognized day: {}", args[1]),
}
}