aizu_online_judge/grl/
grl_5_a.rs

1use competitive::prelude::*;
2#[doc(no_inline)]
3pub use competitive::{algebra::AdditiveOperation, graph::TreeGraphScanner};
4
5#[verify::aizu_online_judge("GRL_5_A")]
6pub fn grl_5_a(reader: impl Read, mut writer: impl Write) {
7    let s = read_all_unchecked(reader);
8    let mut scanner = Scanner::new(&s);
9    scan!(scanner, n, (graph, w): @TreeGraphScanner::<usize, u64>::new(n));
10    let d = graph.weighted_tree_depth::<AdditiveOperation<_>, _>(0, |eid| w[eid]);
11    let r = (0..n).max_by_key(|&u| d[u]).unwrap();
12    let ans = graph
13        .weighted_tree_depth::<AdditiveOperation<_>, _>(r, |eid| w[eid])
14        .into_iter()
15        .max()
16        .unwrap();
17    writeln!(writer, "{}", ans).ok();
18}