#[allow(unused_imports)] use std::cmp::*; #[allow(unused_imports)] use std::collections::*; use std::io::{Write, BufWriter}; // https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8 macro_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, [graph1; $len:expr]) => {{ let mut g = vec![vec![]; $len]; let ab = read_value!($next, [(usize1, usize1)]); for (a, b) in ab { g[a].push(b); g[b].push(a); } g }}; ($next:expr, ( $($t:tt),* )) => { ( $(read_value!($next, $t)),* ) }; ($next:expr, [ $t:tt ; $len:expr ]) => { (0..$len).map(|_| read_value!($next, $t)).collect::>() }; ($next:expr, chars) => { read_value!($next, String).chars().collect::>() }; ($next:expr, usize1) => (read_value!($next, usize) - 1); ($next:expr, [ $t:tt ]) => {{ let len = read_value!($next, usize); read_value!($next, [$t; len]) }}; ($next:expr, $t:ty) => ($next().parse::<$t>().expect("Parse error")); } #[allow(unused)] macro_rules! debug { ($($format:tt)*) => (write!(std::io::stderr(), $($format)*).unwrap()); } #[allow(unused)] macro_rules! debugln { ($($format:tt)*) => (writeln!(std::io::stderr(), $($format)*).unwrap()); } /// Generates an Iterator over subsets of univ, in the descending order. /// Verified by: http://judge.u-aizu.ac.jp/onlinejudge/review.jsp?rid=3050308 struct SubsetIter { bits: Option, univ: usize } impl Iterator for SubsetIter { type Item = usize; fn next(&mut self) -> Option { match self.bits { None => None, Some(bits) => { let ans = bits; self.bits = if bits == 0 { None } else { Some((bits - 1) & self.univ) }; Some(ans) } } } } fn subsets(univ: usize) -> SubsetIter { SubsetIter { bits: Some(univ), univ: univ } } /** * Union-Find tree. * Verified by https://atcoder.jp/contests/pakencamp-2019-day3/submissions/9253305 */ struct UnionFind { disj: Vec, rank: Vec } impl UnionFind { fn new(n: usize) -> Self { let disj = (0..n).collect(); UnionFind { disj: disj, rank: vec![1; n] } } fn root(&mut self, x: usize) -> usize { if x != self.disj[x] { let par = self.disj[x]; let r = self.root(par); self.disj[x] = r; } self.disj[x] } fn unite(&mut self, x: usize, y: usize) { let mut x = self.root(x); let mut y = self.root(y); if x == y { return } if self.rank[x] > self.rank[y] { std::mem::swap(&mut x, &mut y); } self.disj[x] = y; self.rank[y] += self.rank[x]; } #[allow(unused)] fn is_same_set(&mut self, x: usize, y: usize) -> bool { self.root(x) == self.root(y) } #[allow(unused)] fn size(&mut self, x: usize) -> usize { let x = self.root(x); self.rank[x] } } // Tags: steiner-tree fn solve() { let out = std::io::stdout(); let mut out = BufWriter::new(out.lock()); macro_rules! puts { ($($format:tt)*) => (let _ = write!(out,$($format)*);); } input! { n: usize, m: usize, t: usize, abc: [(usize1, usize1, i64); m], v: [usize1; t], } let mut g = vec![vec![]; n]; for &(a, b, c) in &abc { g[a].push((b, c)); g[b].push((a, c)); } const INF: i64 = 1 << 50; if t <= 15 { // O(3^t * poly(n, m)) let mut dp = vec![vec![INF; 1 << t]; n]; for i in 0..t { dp[v[i]][1 << i] = 0; } // Reuse que for performance let mut que = BinaryHeap::new(); for bits in 1usize..1 << t { for sub in subsets(bits) { if sub != 0 && sub != bits { for i in 0..n { dp[i][bits] = min(dp[i][bits], dp[i][sub] + dp[i][bits - sub]); } } } assert!(que.is_empty()); for i in 0..n { que.push((-dp[i][bits], i)); } while let Some((d, v)) = que.pop() { let d = -d; for &(w, c) in &g[v] { if d + c < dp[w][bits] { dp[w][bits] = d + c; que.push((-(d + c), w)); } } } } let mut mi = INF; for i in 0..n { mi = min(mi, dp[i][(1 << t) - 1]); } puts!("{}\n", mi); } else { let mut has = vec![true; n]; for &v in &v { has[v] = false; } let rem: Vec<_> = (0..n).filter(|&i| has[i]).collect(); assert_eq!(rem.len(), n - t); let mut mi = INF; for bits in 0..1 << (n - t) { let mut app = vec![false; n]; let mut nv = 0; for &v in &v { app[v] = true; nv += 1; } for i in 0..n - t { if (bits & 1 << i) != 0 { app[rem[i]] = true; nv += 1; } } let mut edges = vec![]; for a in 0..n { if !app[a] { continue; } for &(b, c) in &g[a] { if a < b && app[b] { edges.push((c, a, b)); } } } edges.sort(); let mut uf = UnionFind::new(n); let mut tot: i64 = 0; let mut conn = nv; for &(c, a, b) in &edges { if uf.is_same_set(a, b) { continue; } uf.unite(a, b); tot += c; conn -= 1; } if conn == 1 { mi = min(mi, tot); } } puts!("{}\n", mi); } } fn main() { // In order to avoid potential stack overflow, spawn a new thread. let stack_size = 104_857_600; // 100 MB let thd = std::thread::Builder::new().stack_size(stack_size); thd.spawn(|| solve()).unwrap().join().unwrap(); }