結果
| 問題 |
No.3206 う し た ウ ニ 木 あ く ん 笑
|
| ユーザー |
 Moss_Local
|
| 提出日時 | 2025-07-18 23:26:44 |
| 言語 | Rust (1.83.0 + proconio) |
| 結果 |
AC
|
| 実行時間 | 194 ms / 3,000 ms |
| コード長 | 4,860 bytes |
| コンパイル時間 | 12,034 ms |
| コンパイル使用メモリ | 400,172 KB |
| 実行使用メモリ | 23,028 KB |
| 最終ジャッジ日時 | 2025-07-18 23:27:04 |
| 合計ジャッジ時間 | 15,650 ms |
|
ジャッジサーバーID （参考情報） |
judge3 / judge1 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 2 |
| other | AC * 30 |
コンパイルメッセージ
warning: variable does not need to be mutable
--> src/main.rs:119:9
|
119 | let mut vec: Vec<i64> = read_vec();
| ----^^^
| |
| help: remove this `mut`
|
= note: `#[warn(unused_mut)]` on by default
warning: variable does not need to be mutable
--> src/main.rs:125:9
|
125 | let mut vec: Vec<i64> = read_vec();
| ----^^^
| |
| help: remove this `mut`
warning: variable does not need to be mutable
--> src/main.rs:130:9
|
130 | let mut vec: Vec<usize> = read_vec();
| ----^^^
| |
| help: remove this `mut`
warning: variable does not need to be mutable
--> src/main.rs:136:9
|
136 | let mut vec: Vec<f64> = read_vec();
| ----^^^
| |
| help: remove this `mut`
warning: variable does not need to be mutable
--> src/main.rs:141:9
|
141 | let mut vec: Vec<char> = read_vec();
| ----^^^
| |
| help: remove this `mut`
warning: variable does not need to be mutable
--> src/main.rs:146:9
|
146 | let mut vec: Vec<usize> = read_vec();
| ----^^^
| |
| help: remove this `mut`
ソースコード
// -*- coding:utf-8-unix -*-
// #![feature(map_first_last)]
#![allow(dead_code)]
#![allow(unused_imports)]
#![allow(unused_macros)]
// use core::num;
use std::cmp::*;
use std::fmt::*;
use std::hash::*;
use std::io::BufRead;
use std::iter::FromIterator;
use std::*;
use std::{cmp, collections, fmt, io, iter, ops, str};
const INF: i64 = 1223372036854775807;
const UINF: usize = INF as usize;
const LINF: i64 = 2147483647;
const INF128: i128 = 1223372036854775807000000000000;
const MOD1: i64 = 1000000007;
const MOD9: i64 = 998244353;
const MOD: i64 = MOD1;
// const MOD: i64 = MOD2;
const UMOD: usize = MOD as usize;
const M_PI: f64 = 3.14159265358979323846;
// use proconio::input;
// const MOD: i64 = INF;
use cmp::Ordering::*;
use std::collections::*;
use std::io::stdin;
use std::io::stdout;
use std::io::Write;
macro_rules! p {
($x:expr) => {
//if expr
println!("{}", $x);
};
}
macro_rules! vp {
// vector print separate with space
($x:expr) => {
println!(
"{}",
$x.iter()
.map(|x| x.to_string())
.collect::<Vec<_>>()
.join(" ")
);
};
}
macro_rules! d {
($x:expr) => {
eprintln!("{:?}", $x);
};
}
macro_rules! yn {
($val:expr) => {
if $val {
println!("Yes");
} else {
println!("No");
}
};
}
macro_rules! map{
// declear btreemap
($($key:expr => $val:expr),*) => {
{
let mut map = ::std::collections::BTreeMap::new();
$(
map.insert($key, $val);
)*
map
}
};
}
macro_rules! set{
// declear btreemap
($($key:expr),*) => {
{
let mut set = ::std::collections::BTreeSet::new();
$(
set.insert($key);
)*
set
}
};
}
//input output
#[allow(dead_code)]
fn read<T: std::str::FromStr>() -> T {
let mut s = String::new();
std::io::stdin().read_line(&mut s).ok();
s.trim().parse().ok().unwrap()
}
#[allow(dead_code)]
fn read_vec<T: std::str::FromStr>() -> Vec<T> {
read::<String>()
.split_whitespace()
.map(|e| e.parse().ok().unwrap())
.collect()
}
#[allow(dead_code)]
fn read_mat<T: std::str::FromStr>(n: u32) -> Vec<Vec<T>> {
(0..n).map(|_| read_vec()).collect()
}
#[allow(dead_code)]
fn readii() -> (i64, i64) {
let mut vec: Vec<i64> = read_vec();
(vec[0], vec[1])
}
#[allow(dead_code)]
fn readiii() -> (i64, i64, i64) {
let mut vec: Vec<i64> = read_vec();
(vec[0], vec[1], vec[2])
}
#[allow(dead_code)]
fn readuu() -> (usize, usize) {
let mut vec: Vec<usize> = read_vec();
(vec[0], vec[1])
}
#[allow(dead_code)]
fn readff() -> (f64, f64) {
let mut vec: Vec<f64> = read_vec();
(vec[0], vec[1])
}
fn readcc() -> (char, char) {
let mut vec: Vec<char> = read_vec();
(vec[0], vec[1])
}
fn readuuu() -> (usize, usize, usize) {
let mut vec: Vec<usize> = read_vec();
(vec[0], vec[1], vec[2])
}
fn main(){
let n: usize = read();
let mut g = vec![Vec::new(); n+1];
for _ in 0..n-1 {
let (u,v): (usize, usize) = readuu();
g[u].push(v);
g[v].push(u);
}
let mut parent = vec![0; n+1];
let mut order = Vec::with_capacity(n);
let mut q = VecDeque::new();
q.push_back(1);
parent[1] = 0;
while let Some(v) = q.pop_front() {
order.push(v);
for &u in &g[v] {
if u == parent[v] { continue; }
parent[u] = v;
q.push_back(u);
}
}
let mut f_down = vec![0; n+1];
for &v in order.iter().rev() {
for &u in &g[v] {
if u == parent[v] { continue; }
f_down[v] = max(f_down[v], f_down[u] + 1);
}
}
let mut f_up = vec![0; n+1];
for &v in &order {
let mut m1: i64 = -1;
let mut m2: i64 = -1;
for &u in &g[v] {
let d = if u == parent[v] { f_up[v] as i64 } else { (f_down[u] + 1) as i64 };
if d >= m1 { m2 = m1; m1 = d; } else if d > m2 { m2 = d; }
}
for &u in &g[v] {
if u == parent[v] { continue; }
let usev = if (f_down[u] + 1) as i64 == m1 { m2 } else { m1 };
f_up[u] = (usev + 1) as usize;
}
}
let mut ans: i64 = 1;
for v in 1..=n {
let mut depths = Vec::with_capacity(g[v].len());
for &u in &g[v] {
if u == parent[v] { depths.push(f_up[v]); } else { depths.push(f_down[u] + 1); }
}
depths.sort_by(|a, b| b.cmp(a));
let mut best: i64 = 0;
for i in 0..depths.len() {
let k = (i + 1) as i64;
let l = depths[i] as i64;
best = max(best, k * l);
}
ans = max(ans, best + 1);
}
p!(ans);
}