結果

問題 No.1320 Two Type Min Cost Cycle
ユーザー ikd
提出日時 2020-12-17 20:28:21
言語 Rust
(1.83.0 + proconio)
結果
AC  
実行時間 483 ms / 2,000 ms
コード長 4,038 bytes
コンパイル時間 18,795 ms
コンパイル使用メモリ 404,812 KB
実行使用メモリ 6,944 KB
最終ジャッジ日時 2024-09-21 08:14:58
合計ジャッジ時間 23,323 ms
ジャッジサーバーID
(参考情報)
judge1 / judge2
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 57
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ソースコード

diff #
プレゼンテーションモードにする

#[derive(Copy, Clone, Debug)]
struct Edge {
to: usize,
cost: u64,
}
fn dijkstra(g: &Vec<Vec<Edge>>, start: usize) -> (Vec<u64>, Vec<Option<usize>>) {
use std::cmp::Reverse;
use std::collections::BinaryHeap;
let n = g.len();
let mut d = vec![std::u64::MAX; n];
let mut q = BinaryHeap::new();
let mut prev = vec![None; n];
d[start] = 0;
q.push((Reverse(0), start));
while let Some((Reverse(c), cur)) = q.pop() {
if c > d[cur] {
continue;
}
for e in &g[cur] {
if c + e.cost < d[e.to] {
d[e.to] = c + e.cost;
prev[e.to] = Some(cur);
q.push((Reverse(d[e.to]), e.to));
}
}
}
(d, prev)
}
fn main() {
let stdin = std::io::stdin();
let mut rd = ProconReader::new(stdin.lock());
let t: usize = rd.get();
let n: usize = rd.get();
let m: usize = rd.get();
let edges: Vec<(usize, usize, u64)> = (0..m)
.map(|_| {
let u: usize = rd.get();
let v: usize = rd.get();
let w: u64 = rd.get();
(u - 1, v - 1, w)
})
.collect();
let solve0 = || {
let mut ans = std::u64::MAX;
for i in 0..m {
let mut g = vec![vec![]; n];
for j in 0..m {
if i == j {
continue;
}
let (u, v, w) = edges[j];
g[u].push(Edge { to: v, cost: w });
g[v].push(Edge { to: u, cost: w });
}
let (u, v, w) = edges[i];
let (d, _) = dijkstra(&g, v);
ans = ans.min(d[u].saturating_add(w));
}
ans
};
let solve1 = || {
let mut ans = std::u64::MAX;
for i in 0..m {
let mut g = vec![vec![]; n];
for j in 0..m {
if i == j {
continue;
}
let (u, v, w) = edges[j];
g[u].push(Edge { to: v, cost: w });
}
let (u, v, w) = edges[i];
let (d, _) = dijkstra(&g, v);
ans = ans.min(d[u].saturating_add(w));
}
ans
};
let ans = match t {
0 => solve0(),
1 => solve1(),
_ => unreachable!(),
};
if ans < std::u64::MAX {
println!("{}", ans);
} else {
println!("{}", -1);
}
}
pub struct ProconReader<R> {
r: R,
line: String,
i: usize,
}
impl<R: std::io::BufRead> ProconReader<R> {
pub fn new(reader: R) -> Self {
Self {
r: reader,
line: String::new(),
i: 0,
}
}
pub fn get<T>(&mut self) -> T
where
T: std::str::FromStr,
<T as std::str::FromStr>::Err: std::fmt::Debug,
{
self.skip_blanks();
assert!(self.i < self.line.len());
assert_ne!(&self.line[self.i..=self.i], " ");
let line = &self.line[self.i..];
let end = line.find(' ').unwrap_or_else(|| line.len());
let s = &line[..end];
self.i += end;
s.parse()
.unwrap_or_else(|_| panic!("parse error `{}`", self.line))
}
fn skip_blanks(&mut self) {
loop {
let start = self.line[self.i..].find(|ch| ch != ' ');
match start {
Some(j) => {
self.i += j;
break;
}
None => {
self.line.clear();
self.i = 0;
let num_bytes = self.r.read_line(&mut self.line).unwrap();
assert!(num_bytes > 0, "reached EOF :(");
self.line = self.line.trim_end_matches(&['\r', '\n'][..]).to_string();
}
}
}
}
pub fn get_vec<T>(&mut self, n: usize) -> Vec<T>
where
T: std::str::FromStr,
<T as std::str::FromStr>::Err: std::fmt::Debug,
{
(0..n).map(|_| self.get()).collect()
}
}
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