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#[derive(Clone, Debug)]
struct Row {
n: u32, b: u32,
palette: Vec<bool>,
max_stone: u32,
width: u32,
stones: Vec<u32>,
max_reachable: u32
}
impl Row {
fn new(n: u32, b: u32) -> Row {
Self {
n, b,
palette: vec![true; n as usize],
max_stone: n,
width: 0,
stones: Vec::with_capacity(n as usize),
max_reachable: n
}
}
fn with_stone(n: u32, b: u32, s: u32) -> Row {
let mut stones = Vec::with_capacity(n as usize);
stones.push(s);
let max_stone = n - if s == n { 1 } else { 0 };
Self {
n, b,
palette: (1..=n).map(|i| i != s).collect(),
max_stone: max_stone,
width: s,
stones,
max_reachable: s + max_stone,
}
}
fn update(&mut self, x: u32) -> bool {
let stone_len = x - self.width;
if stone_len > self.n || !self.palette[(stone_len - 1) as usize] {
return false;
}
self.width = x;
self.palette[(stone_len - 1) as usize] = false;
self.stones.push(stone_len);
if self.max_stone == stone_len {
while !self.palette[(self.max_stone - 1) as usize] {
self.max_stone -= 1;
}
self.max_reachable = x + self.max_stone
} else {
self.max_reachable += stone_len
}
true
}
fn undo_update(&mut self) {
let stone_len = self.stones.pop().unwrap();
self.width -= stone_len;
self.palette[(stone_len - 1) as usize] = true;
if stone_len > self.max_stone {
self.max_stone = stone_len;
self.max_reachable = self.width + stone_len
} else {
self.max_reachable -= stone_len
}
}
fn complete(&mut self) {
self.stones.push(self.b - self.width);
}
fn output_repeat(&self) {
for (i, &stone) in self.stones.iter().enumerate() {
for _ in 0..stone {
print!("{}", ['-', '*'][i & 1]);
}
}
println!("");
}
fn output_numbers(&self) {
for stone in self.stones.iter() {
print!("{:2} ", stone);
}
println!("");
}
}
#[derive(Clone, Debug)]
pub struct Wall {
n: u32, h: u32, b: u32,
rows: Vec<Row>,
x: u32,
min_max_reachable: u32,
max_reached: u32,
steps: u32
}
impl Wall {
pub fn new(n: u32) -> Self {
let (h, b) = ((n >> 1) + 1, (n * n + n ) >> 1);
Self {
n, h, b,
rows: vec![Row::new(n, b); h as usize],
x: 1,
min_max_reachable: n,
max_reached: 0,
steps: 0
}
}
fn new_linear(n: u32) -> Self {
let (h, b) = ((n >> 1) + 1, (n * n + n ) >> 1);
let rows = (1..=h).map(|i| Row::with_stone(n, b, i)).collect();
let x = h + 1;
Self {
n, h, b,
rows,
x,
min_max_reachable: 1 + n,
max_reached: n,
steps: 0
}
}
fn complete(&mut self) {
for row in self.rows.iter_mut() {
row.complete()
}
}
fn order_key(&self, index: u32) -> (i32, i32) {
let row = self.rows.get(index as usize).unwrap();
let stones = row.stones.len() as i32;
let width = row.width as i32;
let max_stone = row.max_stone as i32;
let index = index as i32;
//(-max_stone, index)
let perc = (self.x as f32 / (self.b as f32)) * (self.h as f32);
let dif = (perc - (index as f32)).abs().round() as i32;
(-max_stone, dif)
}
fn order(&self) -> Vec<u32> {
//(0..self.h).collect()
let mut v: Vec<u32> = (0..self.h).collect();
let b = self.b;
v.sort_unstable_by_key(|&row| self.order_key(row));
v
}
pub fn solve(&mut self) -> bool {
self.steps += 1;
// complete if already nearly complete
if self.x == self.b {
self.complete();
return true;
}
let mut row_empty = false;
let min_max_reachable = self.min_max_reachable;
for row_index in self.order() {
if self.rows[row_index as usize].stones.is_empty() {
if row_empty {
break
}
row_empty = true;
}
let max_reachable = self.rows[row_index as usize].max_reachable;
if self.rows[row_index as usize].update(self.x) {
if max_reachable == self.min_max_reachable {
self.min_max_reachable = self.rows.iter()
.map(|v| v.max_reachable).min()
.unwrap();
}
if self.min_max_reachable > self.x {
self.x += 1;
if self.solve() {
return true;
}
self.x -= 1;
}
self.min_max_reachable = min_max_reachable;
self.rows[row_index as usize].undo_update();
}
}
false
}
pub fn output(&self) {
for row in self.rows.iter() {
row.output_numbers();
}
}
}
/*fn main() {
let mut wall = Wall::new(26);
wall.solve();
wall.output();
}*/
|
