結果
問題 | No.2565 はじめてのおつかい |
ユーザー |
![]() |
提出日時 | 2023-12-09 19:42:49 |
言語 | Rust (1.83.0 + proconio) |
結果 |
AC
|
実行時間 | 42 ms / 2,000 ms |
コード長 | 2,636 bytes |
コンパイル時間 | 13,918 ms |
コンパイル使用メモリ | 379,512 KB |
実行使用メモリ | 11,520 KB |
最終ジャッジ日時 | 2024-09-27 03:44:44 |
合計ジャッジ時間 | 16,747 ms |
ジャッジサーバーID (参考情報) |
judge2 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 50 |
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 M = input!(usize); let mut graph = vec![vec![]; N]; for _ in 0..M { let (u, v) = (input!(usize) - 1, input!(usize) - 1); graph[u].push(v); } let bfs = |start: usize| { let mut dist = vec![1_usize << 30; N]; let mut seen = vec![false; N]; let mut q = std::collections::VecDeque::new(); dist[start] = 0; seen[start] = true; q.push_front(start); while let Some(now) = q.pop_front() { for &nxt in graph[now].iter() { if seen[nxt] { continue; } dist[nxt] = dist[now] + 1; seen[nxt] = true; q.push_back(nxt); } } return dist; }; let dist_from0 = bfs(0); let dist_fromNm1 = bfs(N - 2); let dist_fromN = bfs(N - 1); let mut ans = 1_usize << 30; // 1 -> N - 1 -> N -> 1 let ans1 = dist_from0[N - 2] + dist_fromNm1[N - 1] + dist_fromN[0]; // 1 -> N -> N - 1 -> 1 let ans2 = dist_from0[N - 1] + dist_fromN[N - 2] + dist_fromNm1[0]; ans = std::cmp::min(ans, ans1); ans = std::cmp::min(ans, ans2); if ans == 1 << 30 { writeln!(out, "-1"); } else { 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()) } } } }