#[allow(unused_imports)] use std::cmp::{max, min, Ordering}; #[allow(unused_imports)] use std::collections::{HashMap, HashSet}; mod util { use std::io::stdin; use std::str::FromStr; use std::fmt::Debug; #[allow(dead_code)] pub fn line() -> String { let mut line: String = String::new(); stdin().read_line(&mut line).unwrap(); line.trim().to_string() } #[allow(dead_code)] pub fn get() -> T where ::Err: Debug, { let mut line: String = String::new(); stdin().read_line(&mut line).unwrap(); line.trim().parse().unwrap() } #[allow(dead_code)] pub fn gets() -> Vec where ::Err: Debug, { let mut line: String = String::new(); stdin().read_line(&mut line).unwrap(); line.split_whitespace() .map(|t| t.parse().unwrap()) .collect() } #[allow(dead_code)] pub fn get2() -> (T, U) where ::Err: Debug, ::Err: Debug, { let mut line: String = String::new(); stdin().read_line(&mut line).unwrap(); let mut iter = line.split_whitespace(); ( iter.next().unwrap().parse().unwrap(), iter.next().unwrap().parse().unwrap(), ) } #[allow(dead_code)] pub fn get3() -> (S, T, U) where ::Err: Debug, ::Err: Debug, ::Err: Debug, { let mut line: String = String::new(); stdin().read_line(&mut line).unwrap(); let mut iter = line.split_whitespace(); ( iter.next().unwrap().parse().unwrap(), iter.next().unwrap().parse().unwrap(), iter.next().unwrap().parse().unwrap(), ) } } // std::cmp::Reverse doesn't have Clone. #[derive(Eq, PartialEq, Clone)] struct Rev(pub T); impl PartialOrd for Rev { fn partial_cmp(&self, other: &Rev) -> Option { other.0.partial_cmp(&self.0) } } impl Ord for Rev { fn cmp(&self, other: &Rev) -> Ordering { other.0.cmp(&self.0) } } #[allow(unused_macros)] macro_rules! debug { ($x: expr) => { println!("{}: {:?}", stringify!($x), $x) } } fn dfs(i: usize, edges_rev: &Vec>, p: &mut HashSet) -> usize { let l = edges_rev[i] .iter() .map(|&(a, c)| (dfs(a, edges_rev, p) + c, a)) .collect::>(); let longest = l.iter().map(|t| t.0).max().unwrap_or(0); for &(_, a) in l.iter().filter(|t| t.0 < longest) { p.insert(a); } longest } fn main() { let (n, m): (usize, usize) = util::get2(); let abc: Vec<(usize, usize, usize)> = (0..m).map(|_| util::get3()).collect(); let mut edges_rev = vec![Vec::new(); n]; let mut p = HashSet::new(); for &(a, b, c) in &abc { edges_rev[b].push((a, c)); } let t = dfs(n - 1, &edges_rev, &mut p); println!("{} {}/{}", t, p.len(), n); }