結果

問題 No.2236 Lights Out On Simple Graph
ユーザー jiangly
提出日時 2023-03-03 21:59:22
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 3 ms / 4,000 ms
コード長 29,653 bytes
コンパイル時間 4,096 ms
コンパイル使用メモリ 245,628 KB
最終ジャッジ日時 2025-02-11 02:30:42
ジャッジサーバーID
（参考情報） 		judge3 / judge4
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 57
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ソースコード

diff #
プレゼンテーションモードにする

#include <bits/stdc++.h>
using i64 = long long;
using namespace std;
template <typename CostType, typename TotalCostType = int64_t> class MaximumWeightedMatching {
    /*
      Maximum Weighted Matching in General Graphs.
      - O(nm log(n)) time
      - O(n + m) space
      Note: each vertex is 1-indexed.
    */
 public:
    using cost_t = CostType;
    using tcost_t = TotalCostType;
 private:
    enum Label { kSeparated = -2, kInner = -1, kFree = 0, kOuter = 1 };
    static constexpr cost_t Inf = cost_t(1) << (sizeof(cost_t) * 8 - 2);
 private:
    template <typename T> class BinaryHeap {
     public:
        struct Node {
            bool operator<(const Node& rhs) const { return value < rhs.value; }
            T value;
            int id;
        };
        BinaryHeap() {}
        BinaryHeap(int N) : size_(0), node(N + 1), index(N, 0) {}
        int size() const { return size_; }
        bool empty() const { return size_ == 0; }
        void clear() {
            while (size_ > 0) index[node[size_--].id] = 0;
        }
        T min() const { return node[1].value; }
        int argmin() const { return node[1].id; }  // argmin ?
        T get_val(int id) const { return node[index[id]].value; }
        void pop() {
            if (size_ > 0) pop(1);
        }
        void erase(int id) {
            if (index[id]) pop(index[id]);
        }
        bool has(int id) const { return index[id] != 0; }
        void update(int id, T v) {
            if (!has(id)) return push(id, v);
            bool up = (v < node[index[id]].value);
            node[index[id]].value = v;
            if (up) up_heap(index[id]);
            else
                down_heap(index[id]);
        }
        void decrease_key(int id, T v) {
            if (!has(id)) return push(id, v);
            if (v < node[index[id]].value) node[index[id]].value = v, up_heap(index[id]);
        }
        void push(int id, T v) {
            // assert(!has(id));
            index[id] = ++size_;
            node[size_] = {v, id};
            up_heap(size_);
        }
     private:
        void pop(int pos) {
            index[node[pos].id] = 0;
            if (pos == size_) {
                --size_;
                return;
            }
            bool up = (node[size_].value < node[pos].value);
            node[pos] = node[size_--];
            index[node[pos].id] = pos;
            if (up) up_heap(pos);
            else
                down_heap(pos);
        }
        void swap_node(int a, int b) {
            swap(node[a], node[b]);
            index[node[a].id] = a;
            index[node[b].id] = b;
        }
        void down_heap(int pos) {
            for (int k = pos, nk = k; 2 * k <= size_; k = nk) {
                if (node[2 * k] < node[nk]) nk = 2 * k;
                if (2 * k + 1 <= size_ && node[2 * k + 1] < node[nk]) nk = 2 * k + 1;
                if (nk == k) break;
                swap_node(k, nk);
            }
        }
        void up_heap(int pos) {
            for (int k = pos; k > 1 && node[k] < node[k >> 1]; k >>= 1) swap_node(k, k >> 1);
        }
        int size_;
        vector<Node> node;
        vector<int> index;
    };
    template <typename Key> class PairingHeaps {
     private:
        struct Node {
            Node() : prev(-1) {}  // "prev < 0" means the node is unused.
            Node(Key v) : key(v), child(0), next(0), prev(0) {}
            Key key;
            int child, next, prev;
        };
     public:
        PairingHeaps(int H, int N) : heap(H), node(N) {
            // It consists of `H` Pairing heaps.
            // Each heap-node ID can appear at most 1 time(s) among heaps
            // and should be in [1, N).
        }
        void clear(int h) {
            if (heap[h]) clear_rec(heap[h]), heap[h] = 0;
        }
        void clear_all() {
            for (size_t i = 0; i < heap.size(); ++i) heap[i] = 0;
            for (size_t i = 0; i < node.size(); ++i) node[i] = Node();
        }
        bool empty(int h) const { return !heap[h]; }
        bool used(int v) const { return node[v].prev >= 0; }
        Key min(int h) const { return node[heap[h]].key; }
        int argmin(int h) const { return heap[h]; }
        void pop(int h) {
            // assert(!empty(h));
            erase(h, heap[h]);
        }
        void push(int h, int v, Key key) {
            // assert(!used(v));
            node[v] = Node(key);
            heap[h] = merge(heap[h], v);
        }
        void erase(int h, int v) {
            if (!used(v)) return;
            int w = two_pass_pairing(node[v].child);
            if (!node[v].prev) heap[h] = w;
            else {
                cut(v);
                heap[h] = merge(heap[h], w);
            }
            node[v].prev = -1;
        }
        void decrease_key(int h, int v, Key key) {
            if (!used(v)) return push(h, v, key);
            if (!node[v].prev) node[v].key = key;
            else {
                cut(v);
                node[v].key = key;
                heap[h] = merge(heap[h], v);
            }
        }
     private:
        void clear_rec(int v) {
            for (; v; v = node[v].next) {
                if (node[v].child) clear_rec(node[v].child);
                node[v].prev = -1;
            }
        }
        inline void cut(int v) {
            auto& n = node[v];
            int pv = n.prev, nv = n.next;
            auto& pn = node[pv];
            if (pn.child == v) pn.child = nv;
            else
                pn.next = nv;
            node[nv].prev = pv;
            n.next = n.prev = 0;
        }
        int merge(int l, int r) {
            if (!l) return r;
            if (!r) return l;
            if (node[l].key > node[r].key) swap(l, r);
            int lc = node[r].next = node[l].child;
            node[l].child = node[lc].prev = r;
            return node[r].prev = l;
        }
        int two_pass_pairing(int root) {
            if (!root) return 0;
            int a = root;
            root = 0;
            while (a) {
                int b = node[a].next, na = 0;
                node[a].prev = node[a].next = 0;
                if (b) na = node[b].next, node[b].prev = node[b].next = 0;
                a = merge(a, b);
                node[a].next = root;
                root = a;
                a = na;
            }
            int s = node[root].next;
            node[root].next = 0;
            while (s) {
                int t = node[s].next;
                node[s].next = 0;
                root = merge(root, s);
                s = t;
            }
            return root;
        }
     private:
        vector<int> heap;
        vector<Node> node;
    };
    template <typename T> struct PriorityQueue : public priority_queue<T, vector<T>, greater<T> > {
        PriorityQueue() {}
        PriorityQueue(int N) { this->c.reserve(N); }
        T min() { return this->top(); }
        void clear() { this->c.clear(); }
    };
    template <typename T> struct Queue {
        Queue() {}
        Queue(int N) : qh(0), qt(0), data(N) {}
        T operator[](int i) const { return data[i]; }
        void enqueue(int u) { data[qt++] = u; }
        int dequeue() { return data[qh++]; }
        bool empty() const { return qh == qt; }
        void clear() { qh = qt = 0; }
        int size() const { return qt; }
        int qh, qt;
        vector<T> data;
    };
 public:
    struct InputEdge {
        int from, to;
        cost_t cost;
    };
 private:
    template <typename T> using ModifiableHeap = BinaryHeap<T>;
    template <typename T> using ModifiableHeaps = PairingHeaps<T>;
    template <typename T> using FastHeap = PriorityQueue<T>;
    struct Edge {
        int to;
        cost_t cost;
    };
    struct Link {
        int from, to;
    };
    struct Node {
        struct NodeLink {
            int b, v;
        };
        Node() {}
        Node(int u) : parent(0), size(1) { link[0] = link[1] = {u, u}; }
        int next_v() const { return link[0].v; }
        int next_b() const { return link[0].b; }
        int prev_v() const { return link[1].v; }
        int prev_b() const { return link[1].b; }
        int parent, size;
        NodeLink link[2];
    };
    struct Event {
        Event() {}
        Event(cost_t time, int id) : time(time), id(id) {}
        bool operator<(const Event& rhs) const { return time < rhs.time; }
        bool operator>(const Event& rhs) const { return time > rhs.time; }
        cost_t time;
        int id;
    };
    struct EdgeEvent {
        EdgeEvent() {}
        EdgeEvent(cost_t time, int from, int to) : time(time), from(from), to(to) {}
        bool operator>(const EdgeEvent& rhs) const { return time > rhs.time; }
        bool operator<(const EdgeEvent& rhs) const { return time < rhs.time; }
        cost_t time;
        int from, to;
    };
 public:
    MaximumWeightedMatching(int N, const vector<InputEdge>& in)
        : N(N),
          B((N - 1) / 2),
          S(N + B + 1),
          ofs(N + 2),
          edges(in.size() * 2),
          heap2(S),
          heap2s(S, S),
          heap3(edges.size()),
          heap4(S) {
        for (auto& e : in) ofs[e.from + 1]++, ofs[e.to + 1]++;
        for (int i = 1; i <= N + 1; ++i) ofs[i] += ofs[i - 1];
        for (auto& e : in) {
            edges[ofs[e.from]++] = {e.to, e.cost * 2};
            edges[ofs[e.to]++] = {e.from, e.cost * 2};
        }
        for (int i = N + 1; i > 0; --i) ofs[i] = ofs[i - 1];
        ofs[0] = 0;
    }
    pair<tcost_t, vector<int> > maximum_weighted_matching(bool init_matching = false) {
        initialize();
        set_potential();
        if (init_matching) find_maximal_matching();
        for (int u = 1; u <= N; ++u)
            if (!mate[u]) do_edmonds_search(u);
        tcost_t ret = compute_optimal_value();
        return make_pair(ret, mate);
    }
 private:
    tcost_t compute_optimal_value() const {
        tcost_t ret = 0;
        for (int u = 1; u <= N; ++u)
            if (mate[u] > u) {
                cost_t max_c = 0;
                for (int eid = ofs[u]; eid < ofs[u + 1]; ++eid) {
                    if (edges[eid].to == mate[u]) max_c = max(max_c, edges[eid].cost);
                }
                ret += max_c;
            }
        return ret >> 1;
    }
    inline tcost_t reduced_cost(int u, int v, const Edge& e) const {
        return tcost_t(potential[u]) + potential[v] - e.cost;
    }
    void rematch(int v, int w) {
        int t = mate[v];
        mate[v] = w;
        if (mate[t] != v) return;
        if (link[v].to == surface[link[v].to]) {
            mate[t] = link[v].from;
            rematch(mate[t], t);
        } else {
            int x = link[v].from, y = link[v].to;
            rematch(x, y);
            rematch(y, x);
        }
    }
    void fix_mate_and_base(int b) {
        if (b <= N) return;
        int bv = base[b], mv = node[bv].link[0].v, bmv = node[bv].link[0].b;
        int d = (node[bmv].link[1].v == mate[mv]) ? 0 : 1;
        while (1) {
            int mv = node[bv].link[d].v, bmv = node[bv].link[d].b;
            if (node[bmv].link[1 ^ d].v != mate[mv]) break;
            fix_mate_and_base(bv);
            fix_mate_and_base(bmv);
            bv = node[bmv].link[d].b;
        }
        fix_mate_and_base(base[b] = bv);
        mate[b] = mate[bv];
    }
    void reset_time() {
        time_current_ = 0;
        event1 = {Inf, 0};
    }
    void reset_blossom(int b) {
        label[b] = kFree;
        link[b].from = 0;
        slack[b] = Inf;
        lazy[b] = 0;
    }
    void reset_all() {
        label[0] = kFree;
        link[0].from = 0;
        for (int v = 1; v <= N; ++v) {  // should be optimized for sparse graphs.
            if (label[v] == kOuter) potential[v] -= time_current_;
            else {
                int bv = surface[v];
                potential[v] += lazy[bv];
                if (label[bv] == kInner) potential[v] += time_current_ - time_created[bv];
            }
            reset_blossom(v);
        }
        for (int b = N + 1, r = B - unused_bid_idx_; r > 0 && b < S; ++b)
            if (base[b] != b) {
                if (surface[b] == b) {
                    fix_mate_and_base(b);
                    if (label[b] == kOuter) potential[b] += (time_current_ - time_created[b]) << 1;
                    else if (label[b] == kInner)
                        fix_blossom_potential<kInner>(b);
                    else
                        fix_blossom_potential<kFree>(b);
                }
                heap2s.clear(b);
                reset_blossom(b);
                --r;
            }
        que.clear();
        reset_time();
        heap2.clear();
        heap3.clear();
        heap4.clear();
    }
    void do_edmonds_search(int root) {
        if (potential[root] == 0) return;
        link_blossom(surface[root], {0, 0});
        push_outer_and_fix_potentials(surface[root], 0);
        for (bool augmented = false; !augmented;) {
            augmented = augment(root);
            if (augmented) break;
            augmented = adjust_dual_variables(root);
        }
        reset_all();
    }
    template <Label Lab> inline cost_t fix_blossom_potential(int b) {
        // Return the amount.
        // (If v is an atom, the potential[v] will not be changed.)
        cost_t d = lazy[b];
        lazy[b] = 0;
        if (Lab == kInner) {
            cost_t dt = time_current_ - time_created[b];
            if (b > N) potential[b] -= dt << 1;
            d += dt;
        }
        return d;
    }
    template <Label Lab> inline void update_heap2(int x, int y, int by, cost_t t) {
        if (t >= slack[y]) return;
        slack[y] = t;
        best_from[y] = x;
        if (y == by) {
            if (Lab != kInner) heap2.decrease_key(y, EdgeEvent(t + lazy[y], x, y));
        } else {
            int gy = group[y];
            if (gy != y) {
                if (t >= slack[gy]) return;
                slack[gy] = t;
            }
            heap2s.decrease_key(by, gy, EdgeEvent(t, x, y));
            if (Lab == kInner) return;
            EdgeEvent m = heap2s.min(by);
            heap2.decrease_key(by, EdgeEvent(m.time + lazy[by], m.from, m.to));
        }
    }
    void activate_heap2_node(int b) {
        if (b <= N) {
            if (slack[b] < Inf) heap2.push(b, EdgeEvent(slack[b] + lazy[b], best_from[b], b));
        } else {
            if (heap2s.empty(b)) return;
            EdgeEvent m = heap2s.min(b);
            heap2.push(b, EdgeEvent(m.time + lazy[b], m.from, m.to));
        }
    }
    void swap_blossom(int a, int b) {
        // Assume that `b` is a maximal blossom.
        swap(base[a], base[b]);
        if (base[a] == a) base[a] = b;
        swap(heavy[a], heavy[b]);
        if (heavy[a] == a) heavy[a] = b;
        swap(link[a], link[b]);
        swap(mate[a], mate[b]);
        swap(potential[a], potential[b]);
        swap(lazy[a], lazy[b]);
        swap(time_created[a], time_created[b]);
        for (int d = 0; d < 2; ++d) node[node[a].link[d].b].link[1 ^ d].b = b;
        swap(node[a], node[b]);
    }
    void set_surface_and_group(int b, int sf, int g) {
        surface[b] = sf, group[b] = g;
        if (b <= N) return;
        for (int bb = base[b]; surface[bb] != sf; bb = node[bb].next_b()) { set_surface_and_group(bb, sf, g); }
    }
    void merge_smaller_blossoms(int bid) {
        int lb = bid, largest_size = 1;
        for (int beta = base[bid], b = beta;;) {
            if (node[b].size > largest_size) largest_size = node[b].size, lb = b;
            if ((b = node[b].next_b()) == beta) break;
        }
        for (int beta = base[bid], b = beta;;) {
            if (b != lb) set_surface_and_group(b, lb, b);
            if ((b = node[b].next_b()) == beta) break;
        }
        group[lb] = lb;
        if (largest_size > 1) {
            surface[bid] = heavy[bid] = lb;
            swap_blossom(lb, bid);
        } else
            heavy[bid] = 0;
    }
    void contract(int x, int y, int eid) {
        int bx = surface[x], by = surface[y];
        assert(bx != by);
        const int h = -(eid + 1);
        link[surface[mate[bx]]].from = link[surface[mate[by]]].from = h;
        int lca = -1;
        while (1) {
            if (mate[by] != 0) swap(bx, by);
            bx = lca = surface[link[bx].from];
            if (link[surface[mate[bx]]].from == h) break;
            link[surface[mate[bx]]].from = h;
        }
        const int bid = unused_bid[--unused_bid_idx_];
        assert(unused_bid_idx_ >= 0);
        int tree_size = 0;
        for (int d = 0; d < 2; ++d) {
            for (int bv = surface[x]; bv != lca;) {
                int mv = mate[bv], bmv = surface[mv], v = mate[mv];
                int f = link[v].from, t = link[v].to;
                tree_size += node[bv].size + node[bmv].size;
                link[mv] = {x, y};
                if (bv > N) potential[bv] += (time_current_ - time_created[bv]) << 1;
                if (bmv > N) heap4.erase(bmv);
                push_outer_and_fix_potentials(bmv, fix_blossom_potential<kInner>(bmv));
                node[bv].link[d] = {bmv, mv};
                node[bmv].link[1 ^ d] = {bv, v};
                node[bmv].link[d] = {bv = surface[f], f};
                node[bv].link[1 ^ d] = {bmv, t};
            }
            node[surface[x]].link[1 ^ d] = {surface[y], y};
            swap(x, y);
        }
        if (lca > N) potential[lca] += (time_current_ - time_created[lca]) << 1;
        node[bid].size = tree_size + node[lca].size;
        base[bid] = lca;
        link[bid] = link[lca];
        mate[bid] = mate[lca];
        label[bid] = kOuter;
        surface[bid] = bid;
        time_created[bid] = time_current_;
        potential[bid] = 0;
        lazy[bid] = 0;
        merge_smaller_blossoms(bid);  // O(n log n) time / Edmonds search
    }
    void link_blossom(int v, Link l) {
        link[v] = {l.from, l.to};
        if (v <= N) return;
        int b = base[v];
        link_blossom(b, l);
        int pb = node[b].prev_b();
        l = {node[pb].next_v(), node[b].prev_v()};
        for (int bv = b;;) {
            int bw = node[bv].next_b();
            if (bw == b) break;
            link_blossom(bw, l);
            Link nl = {node[bw].prev_v(), node[bv].next_v()};
            bv = node[bw].next_b();
            link_blossom(bv, nl);
        }
    }
    void push_outer_and_fix_potentials(int v, cost_t d) {
        label[v] = kOuter;
        if (v > N) {
            for (int b = base[v]; label[b] != kOuter; b = node[b].next_b()) { push_outer_and_fix_potentials(b, d); }
        } else {
            potential[v] += time_current_ + d;
            if (potential[v] < event1.time) event1 = {potential[v], v};
            que.enqueue(v);
        }
    }
    bool grow(int root, int x, int y) {
        int by = surface[y];
        bool visited = (label[by] != kFree);
        if (!visited) link_blossom(by, {0, 0});
        label[by] = kInner;
        time_created[by] = time_current_;
        heap2.erase(by);
        if (y != by) heap4.update(by, time_current_ + (potential[by] >> 1));
        int z = mate[by];
        if (z == 0 && by != surface[root]) {
            rematch(x, y);
            rematch(y, x);
            return true;
        }
        int bz = surface[z];
        if (!visited) link_blossom(bz, {x, y});
        else
            link[bz] = link[z] = {x, y};
        push_outer_and_fix_potentials(bz, fix_blossom_potential<kFree>(bz));
        time_created[bz] = time_current_;
        heap2.erase(bz);
        return false;
    }
    void free_blossom(int bid) {
        unused_bid[unused_bid_idx_++] = bid;
        base[bid] = bid;
    }
    int recalculate_minimum_slack(int b, int g) {
        // Return the destination of the best edge of blossom `g`.
        if (b <= N) {
            if (slack[b] >= slack[g]) return 0;
            slack[g] = slack[b];
            best_from[g] = best_from[b];
            return b;
        }
        int v = 0;
        for (int beta = base[b], bb = beta;;) {
            int w = recalculate_minimum_slack(bb, g);
            if (w != 0) v = w;
            if ((bb = node[bb].next_b()) == beta) break;
        }
        return v;
    }
    void construct_smaller_components(int b, int sf, int g) {
        surface[b] = sf, group[b] = g;  // `group[b] = g` is unneeded.
        if (b <= N) return;
        for (int bb = base[b]; surface[bb] != sf; bb = node[bb].next_b()) {
            if (bb == heavy[b]) {
                construct_smaller_components(bb, sf, g);
            } else {
                set_surface_and_group(bb, sf, bb);
                int to = 0;
                if (bb > N) slack[bb] = Inf, to = recalculate_minimum_slack(bb, bb);
                else if (slack[bb] < Inf)
                    to = bb;
                if (to > 0) heap2s.push(sf, bb, EdgeEvent(slack[bb], best_from[bb], to));
            }
        }
    }
    void move_to_largest_blossom(int bid) {
        const int h = heavy[bid];
        cost_t d = (time_current_ - time_created[bid]) + lazy[bid];
        lazy[bid] = 0;
        for (int beta = base[bid], b = beta;;) {
            time_created[b] = time_current_;
            lazy[b] = d;
            if (b != h) construct_smaller_components(b, b, b), heap2s.erase(bid, b);
            if ((b = node[b].next_b()) == beta) break;
        }
        if (h > 0) swap_blossom(h, bid), bid = h;
        free_blossom(bid);
    }
    void expand(int bid) {
        int mv = mate[base[bid]];
        move_to_largest_blossom(bid);  // O(n log n) time / Edmonds search
        Link old_link = link[mv];
        int old_base = surface[mate[mv]], root = surface[old_link.to];
        int d = (mate[root] == node[root].link[0].v) ? 1 : 0;
        for (int b = node[old_base].link[d ^ 1].b; b != root;) {
            label[b] = kSeparated;
            activate_heap2_node(b);
            b = node[b].link[d ^ 1].b;
            label[b] = kSeparated;
            activate_heap2_node(b);
            b = node[b].link[d ^ 1].b;
        }
        for (int b = old_base;; b = node[b].link[d].b) {
            label[b] = kInner;
            int nb = node[b].link[d].b;
            if (b == root) link[mate[b]] = old_link;
            else
                link[mate[b]] = {node[b].link[d].v, node[nb].link[d ^ 1].v};
            link[surface[mate[b]]] = link[mate[b]];  // fix tree links
            if (b > N) {
                if (potential[b] == 0) expand(b);
                else
                    heap4.push(b, time_current_ + (potential[b] >> 1));
            }
            if (b == root) break;
            push_outer_and_fix_potentials(nb, fix_blossom_potential<kInner>(b = nb));
        }
    }
    bool augment(int root) {
        // Return true if an augmenting path is found.
        while (!que.empty()) {
            int x = que.dequeue(), bx = surface[x];
            if (potential[x] == time_current_) {
                if (x != root) rematch(x, 0);
                return true;
            }
            for (int eid = ofs[x]; eid < ofs[x + 1]; ++eid) {
                auto& e = edges[eid];
                int y = e.to, by = surface[y];
                if (bx == by) continue;
                Label l = label[by];
                if (l == kOuter) {
                    cost_t t = reduced_cost(x, y, e) >> 1;  // < 2 * Inf
                    if (t == time_current_) {
                        contract(x, y, eid);
                        bx = surface[x];
                    } else if (t < event1.time) {
                        heap3.emplace(t, x, eid);
                    }
                } else {
                    tcost_t t = reduced_cost(x, y, e);  // < 3 * Inf
                    if (t >= Inf) continue;
                    if (l != kInner) {
                        if (cost_t(t) + lazy[by] == time_current_) {
                            if (grow(root, x, y)) return true;
                        } else
                            update_heap2<kFree>(x, y, by, t);
                    } else {
                        if (mate[x] != y) update_heap2<kInner>(x, y, by, t);
                    }
                }
            }
        }
        return false;
    }
    bool adjust_dual_variables(int root) {
        // delta1 : rematch
        cost_t time1 = event1.time;
        // delta2 : grow
        cost_t time2 = Inf;
        if (!heap2.empty()) time2 = heap2.min().time;
        // delta3 : contract : O(m log n) time / Edmonds search [ bottleneck (?) ]
        cost_t time3 = Inf;
        while (!heap3.empty()) {
            EdgeEvent e = heap3.min();
            int x = e.from, y = edges[e.to].to;  // e.to is some edge id.
            if (surface[x] != surface[y]) {
                time3 = e.time;
                break;
            } else
                heap3.pop();
        }
        // delta4 : expand
        cost_t time4 = Inf;
        if (!heap4.empty()) time4 = heap4.min();
        // -- events --
        cost_t time_next = min(min(time1, time2), min(time3, time4));
        assert(time_current_ <= time_next && time_next < Inf);
        time_current_ = time_next;
        if (time_current_ == event1.time) {
            int x = event1.id;
            if (x != root) rematch(x, 0);
            return true;
        }
        while (!heap2.empty() && heap2.min().time == time_current_) {
            int x = heap2.min().from, y = heap2.min().to;
            if (grow(root, x, y)) return true;  // `grow` function will call `heap2.erase(by)`.
        }
        while (!heap3.empty() && heap3.min().time == time_current_) {
            int x = heap3.min().from, eid = heap3.min().to;
            int y = edges[eid].to;
            heap3.pop();
            if (surface[x] == surface[y]) continue;
            contract(x, y, eid);
        }
        while (!heap4.empty() && heap4.min() == time_current_) {
            int b = heap4.argmin();
            heap4.pop();
            expand(b);
        }
        return false;
    }
 private:
    void initialize() {
        que = Queue<int>(N);
        mate.assign(S, 0);
        link.assign(S, {0, 0});
        label.assign(S, kFree);
        base.resize(S);
        for (int u = 1; u < S; ++u) base[u] = u;
        surface.resize(S);
        for (int u = 1; u < S; ++u) surface[u] = u;
        potential.resize(S);
        node.resize(S);
        for (int b = 1; b < S; ++b) node[b] = Node(b);
        unused_bid.resize(B);
        for (int i = 0; i < B; ++i) unused_bid[i] = N + B - i;
        unused_bid_idx_ = B;
        // for O(nm log n) implementation
        reset_time();
        time_created.resize(S);
        slack.resize(S);
        for (int i = 0; i < S; ++i) slack[i] = Inf;
        best_from.assign(S, 0);
        heavy.assign(S, 0);
        lazy.assign(S, 0);
        group.resize(S);
        for (int i = 0; i < S; ++i) group[i] = i;
    }
    void set_potential() {
        for (int u = 1; u <= N; ++u) {
            cost_t max_c = 0;
            for (int eid = ofs[u]; eid < ofs[u + 1]; ++eid) { max_c = max(max_c, edges[eid].cost); }
            potential[u] = max_c >> 1;
        }
    }
    void find_maximal_matching() {
        // Find a maximal matching naively.
        for (int u = 1; u <= N; ++u)
            if (!mate[u]) {
                for (int eid = ofs[u]; eid < ofs[u + 1]; ++eid) {
                    auto& e = edges[eid];
                    int v = e.to;
                    if (mate[v] > 0 || reduced_cost(u, v, e) > 0) continue;
                    mate[u] = v;
                    mate[v] = u;
                    break;
                }
            }
    }
 private:
    int N, B, S;  // N = |V|, B = (|V| - 1) / 2, S = N + B + 1
    vector<int> ofs;
    vector<Edge> edges;
    Queue<int> que;
    vector<int> mate, surface, base;
    vector<Link> link;
    vector<Label> label;
    vector<cost_t> potential;
    vector<int> unused_bid;
    int unused_bid_idx_;
    vector<Node> node;
    // for O(nm log n) implementation
    vector<int> heavy, group;
    vector<cost_t> time_created, lazy, slack;
    vector<int> best_from;
    cost_t time_current_;
    Event event1;
    ModifiableHeap<EdgeEvent> heap2;
    ModifiableHeaps<EdgeEvent> heap2s;
    FastHeap<EdgeEvent> heap3;
    ModifiableHeap<cost_t> heap4;
};
constexpr int inf = 1E4;
int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    
    int N, M;
    std::cin >> N >> M;
    
    std::vector d(N, std::vector(N, inf));
    
    for (int i = 0; i < N; i++) {
        d[i][i] = 0;
    }
    for (int i = 0; i < M; i++) {
        int A, B;
        std::cin >> A >> B;
        A--, B--;
        d[A][B] = d[B][A] = 1;
    }
    
    for (int k = 0; k < N; k++) {
        for (int i = 0; i < N; i++) {
            for (int j = 0; j < N; j++) {
                d[i][j] = std::min(d[i][j], d[i][k] + d[k][j]);
            }
        }
    }
    
    std::vector<int> c(N);
    std::vector<int> a;
    for (int i = 0; i < N; i++) {
        std::cin >> c[i];
        if (c[i] == 1) {
            a.push_back(i);
        }
    }
    
    if (a.size() % 2 == 1) {
        std::cout << -1 << "\n";
        return 0;
    }
    
    std::vector<MaximumWeightedMatching<int>::InputEdge> edges;
    for (int i = 0; i < a.size(); i++) {
        for (int j = i + 1; j < a.size(); j++) {
            edges.push_back({i + 1, j + 1, inf - d[a[i]][a[j]]});
        }
    }
    
    int ans = MaximumWeightedMatching<int>(a.size(), edges).maximum_weighted_matching().first;
    ans = a.size() / 2 * inf - ans;
    if (ans >= inf) {
        ans = -1;
    }
    std::cout << ans << "\n";
    
    return 0;
}
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