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extern crate advent_of_code_2018;
use advent_of_code_2018::*;
use std::error::Error;
use std::i32;
// cargo watch -cs "cargo run --release --bin day_11"
fn main() -> Result<(), Box<Error>> {
let input = 1723;
println!("Input: {:?}", input);
let powers = precompute_powers(input);
let power_per_size = (1..300).map(|size| {
(1..302-size).map(|left| {
(1..302-size).map(|top| {
(power_for_block(left, top, size, &powers), (left, top, size))
}).max_by_key(|(p, _)| *p).unwrap()
}).max_by_key(|(p, _)| *p).unwrap()
}).collect::<Vec<_>>();
let (max_power_at_size_3, coordinate_at_size_3) = power_per_size[2]; // index from 0 vs 1
debug!(max_power_at_size_3);
debug!(coordinate_at_size_3);
let (max_power, coordinate) = power_per_size.iter().max_by_key(|(p, _)| p).unwrap();
debug!(max_power);
debug!(coordinate);
Ok(())
}
fn power_for_block(left: i32, top: i32, size: i32, powers: &[[i32;300];300]) -> i32 {
(left..left+size).map(|x| {
(top..top+size).map(|y| {
powers[x as usize - 1][y as usize - 1]
}).sum::<i32>()
}).sum()
}
fn precompute_powers(input: i32) -> [[i32;300];300] {
let mut powers: [[i32;300];300] = [[0;300];300];
for x in 1..301 {
for y in 1..301 {
powers[x as usize - 1][y as usize - 1] = power_from_coordinates(x, y, input);
}
}
powers
}
fn power_from_coordinates(x: i32, y: i32, input: i32) -> i32 {
let rack_id = x + 10;
((((rack_id * y) + input) * rack_id / 100) % 10) - 5
}
#[test]
fn power_from_coord_example() {
assert_eq!(power_from_coordinates(3, 5, 8), 4);
assert_eq!(power_from_coordinates(122, 79, 57), -5);
assert_eq!(power_from_coordinates(217,196, 39), 0);
assert_eq!(power_from_coordinates(101, 153, 71), 4);
}
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