結果

問題 No.2712 Play more!
ユーザー nautnaut
提出日時 2024-03-31 14:28:59
言語 Rust
(1.77.0)
結果
RE  
実行時間 -
コード長 4,422 bytes
コンパイル時間 1,929 ms
コンパイル使用メモリ 188,120 KB
実行使用メモリ 6,676 KB
最終ジャッジ日時 2024-03-31 14:29:06
合計ジャッジ時間 3,951 ms
ジャッジサーバーID
（参考情報） 		judge15 / judge13
このコードへのチャレンジ
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 1 ms
6,676 KB
testcase_01 AC 1 ms
6,676 KB
testcase_02 AC 1 ms
6,676 KB
testcase_03 AC 1 ms
6,676 KB
testcase_04 RE -
testcase_05 RE -
testcase_06 RE -
testcase_07 RE -
testcase_08 RE -
testcase_09 AC 40 ms
6,676 KB
testcase_10 RE -
testcase_11 AC 67 ms
6,676 KB
testcase_12 AC 36 ms
6,676 KB
testcase_13 AC 56 ms
6,676 KB
testcase_14 RE -
testcase_15 AC 112 ms
6,676 KB
testcase_16 AC 127 ms
6,676 KB
testcase_17 AC 34 ms
6,676 KB
testcase_18 AC 11 ms
6,676 KB
testcase_19 AC 12 ms
6,676 KB
testcase_20 AC 119 ms
6,676 KB
testcase_21 AC 273 ms
6,676 KB
testcase_22 AC 43 ms
6,676 KB
testcase_23 AC 228 ms
6,676 KB
testcase_24 AC 39 ms
6,676 KB
testcase_25 AC 105 ms
6,676 KB
testcase_26 AC 13 ms
6,676 KB
testcase_27 RE -
testcase_28 AC 5 ms
6,676 KB
testcase_29 AC 38 ms
6,676 KB
testcase_30 RE -
testcase_31 AC 134 ms
6,676 KB
testcase_32 AC 75 ms
6,676 KB
testcase_33 AC 2 ms
6,676 KB
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ソースコード

diff # 

#![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 A = input!(isize, N);

    let mut edges = vec![];

    for _ in 0..M {
        let a = input!(usize) - 1;
        let b = input!(usize) - 1;
        let c = input!(isize);

        edges.push((a, b, c - A[a]));
    }

    let ans = bellman_ford_algorithm(N, &edges, 0);
    let ans2 = bellman_ford_algorithm2(N, &edges, 0);

    if let Some(_) = ans {
        let dist2 = ans2.unwrap();
        writeln!(out, "{}", -dist2[N - 1].unwrap() + A[N - 1]);
    } else {
        writeln!(out, "inf");
    }
}

pub fn bellman_ford_algorithm<
    W: Sized + std::ops::Add<Output = W> + PartialOrd + Ord + Default + Clone + Copy,
>(
    size: usize,
    directed_edges: &[(usize, usize, W)],
    start: usize,
) -> Option<Vec<Option<W>>> {
    assert!(start < size);

    let mut dist = vec![None; size];
    dist[start] = Some(W::default());

    for _ in 0..directed_edges.len() {
        for &(u, v, w) in directed_edges.iter() {
            let dv = dist[v];
            let du = dist[u];

            if let Some(du) = du {
                if let Some(dv) = dv {
                    if dv > du + w {
                        dist[v] = Some(du + w);
                    }
                } else {
                    dist[v] = Some(du + w);
                }
            }
        }
    }

    let dist_prev = dist.clone();

    for &(u, v, w) in directed_edges.iter() {
        let dv = dist[v];
        let du = dist[u];

        if let Some(du) = du {
            if let Some(dv) = dv {
                if dv > du + w {
                    dist[v] = Some(du + w);
                }
            } else {
                dist[v] = Some(du + w);
            }
        }
    }

    if dist[size - 1] != dist_prev[size - 1] {
        return None;
    } else {
        return Some(dist);
    }
}

pub fn bellman_ford_algorithm2<
    W: Sized + std::ops::Add<Output = W> + PartialOrd + Ord + Default + Clone + Copy,
>(
    size: usize,
    directed_edges: &[(usize, usize, W)],
    start: usize,
) -> Option<Vec<Option<W>>> {
    assert!(start < size);

    let mut dist = vec![None; size];
    dist[start] = Some(W::default());

    for _ in 0..directed_edges.len() {
        for &(u, v, w) in directed_edges.iter() {
            let dv = dist[v];
            let du = dist[u];

            if let Some(du) = du {
                if let Some(dv) = dv {
                    if dv > du + w {
                        dist[v] = Some(du + w);
                    }
                } else {
                    dist[v] = Some(du + w);
                }
            }
        }
    }

    let dist_prev = dist.clone();

    for &(u, v, w) in directed_edges.iter() {
        let dv = dist[v];
        let du = dist[u];

        if let Some(du) = du {
            if let Some(dv) = dv {
                if dv > du + w {
                    dist[v] = Some(du + w);
                }
            } else {
                dist[v] = Some(du + w);
            }
        }
    }

    if dist == dist_prev {
        Some(dist)
    } else {
        None
    }
}
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())
            }
        }
    }
}
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