結果
問題 | No.2638 Initial fare |
ユーザー |
![]() |
提出日時 | 2024-02-19 22:24:13 |
言語 | Rust (1.83.0 + proconio) |
結果 |
AC
|
実行時間 | 169 ms / 2,000 ms |
コード長 | 2,732 bytes |
コンパイル時間 | 13,737 ms |
コンパイル使用メモリ | 391,124 KB |
実行使用メモリ | 26,144 KB |
最終ジャッジ日時 | 2024-09-29 02:17:53 |
合計ジャッジ時間 | 17,929 ms |
ジャッジサーバーID (参考情報) |
judge1 / judge2 |
(要ログイン)
ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 25 |
ソースコード
#![allow(non_snake_case, unused_imports, unused_must_use)]use std::io::{self, prelude::*};use std::str;fn main() {let (stdin, stdout) = (io::stdin(), io::stdout());let mut scan = Scanner::new(stdin.lock());let mut out = io::BufWriter::new(stdout.lock());macro_rules! input {($T: ty) => {scan.token::<$T>()};($T: ty, $N: expr) => {(0..$N).map(|_| scan.token::<$T>()).collect::<Vec<_>>()};}let N = input!(usize);let mut graph = vec![vec![]; N];for _ in 0..N - 1 {let (u, v) = (input!(usize) - 1, input!(usize) - 1);graph[u].push(v);graph[v].push(u);}let r = 0;let mut dist = vec![0; N];let mut seen = vec![false; N];let mut q = std::collections::VecDeque::new();q.push_back(r);seen[r] = true;while let Some(now) = q.pop_front() {for &nxt in graph[now].iter() {if seen[nxt] {continue;}q.push_back(nxt);dist[nxt] = dist[now] + 1;seen[nxt] = true;}}let mut ans = 0;let mut dp1 = vec![0; N];let mut dp2 = vec![0; N];let mut dp3 = vec![0; N];let mut order = (0..N).map(|i| i).collect::<Vec<_>>();order.sort_by_key(|&i| dist[i]);order.reverse();for v in order {if v != r {dp1[v] = graph[v].len() - 1;} else {dp1[v] = graph[v].len();}for &nxt in graph[v].iter() {if dist[nxt] <= dist[v] {continue;}dp2[v] += dp1[nxt];dp3[v] += dp2[nxt];}ans += dp1[v] + dp2[v] + dp3[v];if dp1[v] != 0 {ans += (dp1[v] - 1) * dp2[v] + (dp1[v] - 1) * dp1[v] / 2;}}writeln!(out, "{}", ans);}struct Scanner<R> {reader: R,buf_str: Vec<u8>,buf_iter: str::SplitWhitespace<'static>,}impl<R: BufRead> Scanner<R> {fn new(reader: R) -> Self {Self {reader,buf_str: vec![],buf_iter: "".split_whitespace(),}}fn token<T: str::FromStr>(&mut self) -> T {loop {if let Some(token) = self.buf_iter.next() {return token.parse().ok().expect("Failed parse");}self.buf_str.clear();self.reader.read_until(b'\n', &mut self.buf_str).expect("Failed read");self.buf_iter = unsafe {let slice = str::from_utf8_unchecked(&self.buf_str);std::mem::transmute(slice.split_whitespace())}}}}