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use std::cmp::{max, Eq, PartialEq};
use std::collections::HashMap;
use std::hash::{Hash, Hasher};
#[derive(Debug, Clone)]
struct Node {
name: u16,
rate: usize,
neighbors: Vec<u16>,
valve_on: bool
}
#[derive(Debug, Clone)]
struct Map {
index: HashMap<u16, usize>,
nodes: Vec<Node>,
pos: u16
}
fn getname(line: &str) -> u16 {
100 * (line.chars().nth(0).unwrap() as u16) +
(line.chars().nth(1).unwrap() as u16)
}
impl Node {
fn from_line(line: &str) -> Node {
let name = getname(&line[6..]);
let j = line.find(';').unwrap();
let rate = line[23..j].parse::<usize>().unwrap();
let mut neighbors = vec![];
let mut i = j+24;
// "tunnels lead to valves" vs "tunnel lead to valve"
// What kind of sadistic animal made these inputs?
if line.chars().nth(i).unwrap() == ' ' { i += 1; }
while i < line.len() {
neighbors.push(getname(&line[i..]));
i += 4;
}
Node { name, rate, neighbors, valve_on: false }
}
}
impl Map {
fn from_stdin() -> Map {
let mut line = String::new();
let mut nodes = Vec::<Node>::new();
while std::io::stdin().read_line(&mut line).unwrap() > 0 {
let node = Node::from_line(&line);
if nodes.len() > 0 && node.name == getname("AA") {
nodes.push(nodes[0].clone());
nodes[0] = node;
} else {
nodes.push(node);
}
line.clear();
}
let index = nodes.iter()
.enumerate()
.map(|(i, n)| (n.name, i))
.collect::<HashMap<_, _>>();
Map { index, nodes, pos: getname("AA") }
}
fn get_state(&self) -> usize {
let mut i: usize = 0;
let mut tot: usize = 0;
for n in &self.nodes {
if n.rate == 0 { continue; }
if n.valve_on { tot += 1 << i; }
i += 1;
}
tot * self.nodes.len() + self.index[&self.pos]
}
fn set_state(&mut self, state: usize) {
let mut s = state;
let len = self.nodes.len();
self.pos = self.nodes[s%len].name;
s /= len;
for i in 0..len {
if self.nodes[i].rate == 0 { continue; }
self.nodes[i].valve_on = s % 2 == 1;
s /= 2;
}
}
fn state_max(&self) -> usize {
let mut i: usize = 0;
let mut tot: usize = 0;
for n in &self.nodes {
if n.rate == 0 { continue; }
tot += 1 << i;
i += 1;
}
let len = self.nodes.len();
tot * len + len
}
fn released_pressure(&self) -> usize {
self.nodes.iter()
.map(|n| if n.valve_on { n.rate } else { 0 })
.sum()
}
/*
fn most_pressure(&self, minutes: usize) -> usize {
let n = self.state_max();
let mut t = vec![0 as usize; n];
let mut u = vec![0 as usize; n];
let mut map = self.clone();
// Setup table for last minute
for s in 0..n {
map.set_state(s);
t[s] = map.released_pressure();
}
// Dynamic programming counting back to 0 minutes
for i in (0..minutes).rev() {
// Double buffer technique so we don't have to swap vectors
let (current, next) = if i % 2 == minutes % 2 {
(&mut t, &mut u)
} else {
(&mut u, &mut t)
};
for s in 0..n {
map.set_state(s);
let pos = map.pos;
let mut k = 0;
let ind = map.index[&pos];
let p = map.released_pressure();
// Try turning on the valve
if map.nodes[ind].rate > 0 && !map.nodes[ind].valve_on {
map.nodes[ind].valve_on = true;
k = max(k, p + next[map.get_state()]);
map.nodes[ind].valve_on = false;
}
// Try moving to a neighbor
for v in &map.nodes[ind].neighbors {
map.pos = *v;
k = max(k, p + next[map.get_state()]);
}
current[s] = k;
}
}
if 0 == minutes % 2 { t[0] } else { u[0] }
}
*/
fn most_pressure(&self, minutes: usize) -> usize {
let n = self.state_max();
let mut t = vec![0 as usize; n];
let mut u = vec![0 as usize; n];
let mut map = self.clone();
// Setup table for last minute
for s in 0..n {
map.set_state(s);
t[s] = map.released_pressure();
}
// Dynamic programming counting back to 0 minutes
for i in (0..minutes).rev() {
// Double buffer technique so we don't have to swap vectors
let (current, next) = if i % 2 == minutes % 2 {
(&mut t, &mut u)
} else {
(&mut u, &mut t)
};
for s in 0..n {
map.set_state(s);
let pos = map.pos;
let mut k = 0;
let ind = map.index[&pos];
let p = map.released_pressure();
// Try turning on the valve
if map.nodes[ind].rate > 0 && !map.nodes[ind].valve_on {
map.nodes[ind].valve_on = true;
k = max(k, p + next[map.get_state()]);
map.nodes[ind].valve_on = false;
}
// Try moving to a neighbor
for v in &map.nodes[ind].neighbors {
map.pos = *v;
k = max(k, p + next[map.get_state()]);
}
current[s] = k;
}
}
if 0 == minutes % 2 { t[0] } else { u[0] }
}
}
impl PartialEq for Map {
fn eq(&self, other: &Self) -> bool {
self.get_state() == other.get_state()
}
}
impl Eq for Map {}
impl Hash for Map {
fn hash<H: Hasher>(&self, hasher: &mut H) {
hasher.write_usize(self.get_state());
}
}
fn main() {
let map = Map::from_stdin();
let mut t = HashMap::<Map, usize>::new();
println!("{}", map.most_pressure(29, t));
}
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