結果

問題 No.1553 Lovely City
ユーザー akakimidori
提出日時 2021-06-18 23:08:34
言語 Rust
(1.83.0 + proconio)
結果
AC  
実行時間 172 ms / 2,000 ms
コード長 5,060 bytes
コンパイル時間 12,259 ms
コンパイル使用メモリ 378,708 KB
実行使用メモリ 32,316 KB
最終ジャッジ日時 2024-06-22 21:20:58
合計ジャッジ時間 19,157 ms
ジャッジサーバーID
(参考情報)
judge4 / judge5
このコードへのチャレンジ
(要ログイン)
ファイルパターン 結果
sample AC * 2
other AC * 26
権限があれば一括ダウンロードができます

ソースコード

diff #
プレゼンテーションモードにする

//---------- begin union_find ----------
pub struct DSU {
p: Vec<i32>,
}
impl DSU {
pub fn new(n: usize) -> DSU {
assert!(n < std::i32::MAX as usize);
DSU { p: vec![-1; n] }
}
pub fn init(&mut self) {
self.p.iter_mut().for_each(|p| *p = -1);
}
pub fn root(&self, mut x: usize) -> usize {
assert!(x < self.p.len());
while self.p[x] >= 0 {
x = self.p[x] as usize;
}
x
}
pub fn same(&self, x: usize, y: usize) -> bool {
assert!(x < self.p.len() && y < self.p.len());
self.root(x) == self.root(y)
}
pub fn unite(&mut self, x: usize, y: usize) -> Option<(usize, usize)> {
assert!(x < self.p.len() && y < self.p.len());
let mut x = self.root(x);
let mut y = self.root(y);
if x == y {
return None;
}
if self.p[x] > self.p[y] {
std::mem::swap(&mut x, &mut y);
}
self.p[x] += self.p[y];
self.p[y] = x as i32;
Some((x, y))
}
pub fn parent(&self, x: usize) -> Option<usize> {
assert!(x < self.p.len());
let p = self.p[x];
if p >= 0 {
Some(p as usize)
} else {
None
}
}
pub fn sum<F>(&self, mut x: usize, mut f: F) -> usize
where
F: FnMut(usize),
{
while let Some(p) = self.parent(x) {
f(x);
x = p;
}
x
}
pub fn size(&self, x: usize) -> usize {
assert!(x < self.p.len());
let r = self.root(x);
(-self.p[r]) as usize
}
}
//---------- end union_find ----------
// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
(source = $s:expr, $($r:tt)*) => {
let mut iter = $s.split_whitespace();
input_inner!{iter, $($r)*}
};
($($r:tt)*) => {
let s = {
use std::io::Read;
let mut s = String::new();
std::io::stdin().read_to_string(&mut s).unwrap();
s
};
let mut iter = s.split_whitespace();
input_inner!{iter, $($r)*}
};
}
macro_rules! input_inner {
($iter:expr) => {};
($iter:expr, ) => {};
($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
let $var = read_value!($iter, $t);
input_inner!{$iter $($r)*}
};
}
macro_rules! read_value {
($iter:expr, ( $($t:tt),* )) => {
( $(read_value!($iter, $t)),* )
};
($iter:expr, [ $t:tt ; $len:expr ]) => {
(0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
};
($iter:expr, chars) => {
read_value!($iter, String).chars().collect::<Vec<char>>()
};
($iter:expr, bytes) => {
read_value!($iter, String).bytes().collect::<Vec<u8>>()
};
($iter:expr, usize1) => {
read_value!($iter, usize) - 1
};
($iter:expr, $t:ty) => {
$iter.next().unwrap().parse::<$t>().expect("Parse error")
};
}
// ---------- end input macro ----------
fn run() {
input! {
n: usize,
m: usize,
cond: [(usize1, usize1); m],
}
let mut dsu = DSU::new(n);
let mut edge = vec![vec![]; n];
for (a, b) in cond {
if let Some((x, y)) = dsu.unite(a, b) {
let mut p = std::mem::take(&mut edge[y]);
edge[x].append(&mut p);
}
edge[dsu.root(a)].push((a, b));
}
let mut ans = vec![];
for i in 0..n {
if i != dsu.root(i) {
continue;
}
let edge = std::mem::take(&mut edge[i]);
let mut z = vec![];
z.extend(edge.iter().map(|e| e.0));
z.extend(edge.iter().map(|e| e.1));
z.sort();
z.dedup();
let n = z.len();
let mut g = vec![vec![]; n];
let mut deg = vec![0; n];
for &(a, b) in edge.iter() {
let a = z.binary_search(&a).unwrap();
let b = z.binary_search(&b).unwrap();
deg[b] += 1;
g[a].push(b);
}
let mut topo = vec![];
for i in 0..n {
if deg[i] == 0 {
topo.push(i);
}
}
for i in 0..n {
if i >= topo.len() {
break;
}
let v = topo[i];
for &u in g[v].iter() {
deg[u] -= 1;
if deg[u] == 0 {
topo.push(u);
}
}
}
if topo.len() == n {
for e in topo.windows(2) {
ans.push((z[e[0]], z[e[1]]));
}
} else {
let f = z[0];
z.push(f);
for z in z.windows(2) {
ans.push((z[0], z[1]));
}
}
}
use std::io::Write;
let out = std::io::stdout();
let mut out = std::io::BufWriter::new(out.lock());
writeln!(out, "{}", ans.len()).ok();
for a in ans {
writeln!(out, "{} {}", a.0 + 1, a.1 + 1).ok();
}
}
fn main() {
run();
}
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