結果
問題 | No.626 Randomized 01 Knapsack |
ユーザー |
|
提出日時 | 2021-09-28 18:38:39 |
言語 | Rust (1.83.0 + proconio) |
結果 |
AC
|
実行時間 | 4 ms / 2,000 ms |
コード長 | 2,867 bytes |
コンパイル時間 | 12,716 ms |
コンパイル使用メモリ | 387,560 KB |
実行使用メモリ | 6,948 KB |
最終ジャッジ日時 | 2024-07-08 02:10:43 |
合計ジャッジ時間 | 14,288 ms |
ジャッジサーバーID (参考情報) |
judge5 / judge2 |
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ファイルパターン | 結果 |
---|---|
other | AC * 25 |
ソースコード
#[allow(unused_imports)]use std::cmp::*;// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8macro_rules! input {($($r:tt)*) => {let stdin = std::io::stdin();let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));let mut next = move || -> String{bytes.by_ref().map(|r|r.unwrap() as char).skip_while(|c|c.is_whitespace()).take_while(|c|!c.is_whitespace()).collect()};input_inner!{next, $($r)*}};}macro_rules! input_inner {($next:expr) => {};($next:expr,) => {};($next:expr, $var:ident : $t:tt $($r:tt)*) => {let $var = read_value!($next, $t);input_inner!{$next $($r)*}};}macro_rules! read_value {($next:expr, ( $($t:tt),* )) => { ($(read_value!($next, $t)),*) };($next:expr, [ $t:tt ; $len:expr ]) => {(0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()};($next:expr, $t:ty) => ($next().parse::<$t>().expect("Parse error"));}trait Change { fn chmax(&mut self, x: Self); fn chmin(&mut self, x: Self); }impl<T: PartialOrd> Change for T {fn chmax(&mut self, x: T) { if *self < x { *self = x; } }fn chmin(&mut self, x: T) { if *self > x { *self = x; } }}fn main() {// In order to avoid potential stack overflow, spawn a new thread.let stack_size = 104_857_600; // 100 MBlet thd = std::thread::Builder::new().stack_size(stack_size);thd.spawn(|| solve()).unwrap().join().unwrap();}fn dfs(vw: &[(i64, i64)], pos: usize, mut vsum: i64, mut wsum: i64, lim: i64, acc: i64, ma: &mut i64) {if *ma >= acc + vsum {return;}if lim >= wsum {ma.chmax(acc + vsum);return;}ma.chmax(acc);if pos >= vw.len() {return;}let mut rel = acc;let mut rem = lim;for i in pos..vw.len() {let (v, w) = vw[i];if rem >= w {rel += v;rem -= w;} else {rel += ((v as i128 * rem as i128) / w as i128) as i64;break;}}if rel <= *ma {return;}let to = min(vw.len(), pos + 10);for i in pos..to {let (v, w) = vw[i];vsum -= v;wsum -= w;if lim >= w {dfs(vw, i + 1, vsum, wsum, lim - w, acc + v, ma);}}dfs(vw, to, vsum, wsum, lim, acc, ma);}// The author read the editorial before implementing this.fn solve() {input! {n: usize, lim: i64,vw: [(i64, i64); n],}let mut vw = vw;vw.sort_by_key(|&(v, w)| -v * 1_000_000 / w);let mut ma = 0;let mut vsum = 0;let mut wsum = 0;for i in 0..n {vsum += vw[i].0;wsum += vw[i].1;}dfs(&vw, 0, vsum, wsum, lim, 0, &mut ma);println!("{}", ma);}