package main import ( "bufio" "fmt" "math/bits" "os" "sort" "strings" ) func main() { in := bufio.NewReader(os.Stdin) out := bufio.NewWriter(os.Stdout) defer out.Flush() var n, m, k int fmt.Fscan(in, &n, &m, &k) edges := make([][]int, 0, m) for i := 0; i < m; i++ { var u, v, w int fmt.Fscan(in, &u, &v, &w) u, v = u-1, v-1 edges = append(edges, []int{u, v, w}) } criticals := make([]int, k) for i := 0; i < k; i++ { fmt.Fscan(in, &criticals[i]) criticals[i]-- } fmt.Fprintln(out, solve(n, edges, criticals)) } func solve(n int, edges [][]int, criticals []int) int { if len(criticals) <= 15 { return MinimumSteinerTree(n, edges, criticals) } sort.Slice(edges, func(i, j int) bool { return edges[i][2] < edges[j][2] }) notCriticals := []int{} set := map[int]struct{}{} for _, c := range criticals { set[c] = struct{}{} } for i := 0; i < n; i++ { if _, ok := set[i]; !ok { notCriticals = append(notCriticals, i) } } // 选择点集state时,连通criticals的最小边权之和 cal := func(state int) int { uf := NewUnionFindArray(n) ok := 0 cost := 0 for _, e := range edges { u, v, w := e[0], e[1], e[2] if state&(1< 0 { u := q[0] q = q[1:] visited[u] = false for _, e := range graph[u] { v, w := e[0], e[1] if dp[s][u]+w < dp[s][v] { dp[s][v] = dp[s][u] + w if !visited[v] { q = append(q, v) visited[v] = true } } } } } for s := 1; s < (1 << k); s++ { for t := s & (s - 1); t > 0; t = (t - 1) & s { if t < (s ^ t) { break } for i := 0; i < n; i++ { dp[s][i] = min(dp[s][i], dp[t][i]+dp[t^s][i]) } } spfa(s) } res := INF for i := 0; i < n; i++ { res = min(res, dp[(1< ufa.rank[root2] { root1, root2 = root2, root1 } ufa.parent[root1] = root2 ufa.rank[root2] += ufa.rank[root1] ufa.Part-- return true } func (ufa *UnionFindArray) UnionWithCallback(key1, key2 int, cb func(big, small int)) bool { root1, root2 := ufa.Find(key1), ufa.Find(key2) if root1 == root2 { return false } if ufa.rank[root1] > ufa.rank[root2] { root1, root2 = root2, root1 } ufa.parent[root1] = root2 ufa.rank[root2] += ufa.rank[root1] ufa.Part-- cb(root2, root1) return true } func (ufa *UnionFindArray) Find(key int) int { for ufa.parent[key] != key { ufa.parent[key] = ufa.parent[ufa.parent[key]] key = ufa.parent[key] } return key } func (ufa *UnionFindArray) IsConnected(key1, key2 int) bool { return ufa.Find(key1) == ufa.Find(key2) } func (ufa *UnionFindArray) GetGroups() map[int][]int { groups := make(map[int][]int) for i := 0; i < ufa.n; i++ { root := ufa.Find(i) groups[root] = append(groups[root], i) } return groups } func (ufa *UnionFindArray) Size(key int) int { return ufa.rank[ufa.Find(key)] } func (ufa *UnionFindArray) String() string { sb := []string{"UnionFindArray:"} for root, member := range ufa.GetGroups() { cur := fmt.Sprintf("%d: %v", root, member) sb = append(sb, cur) } sb = append(sb, fmt.Sprintf("Part: %d", ufa.Part)) return strings.Join(sb, "\n") }