2001. [HNOI2010] City 城市建设

https://hydro.ac/d/bzoj/record/63b3a21498c0c23d298667ca

BZOJ/2001/2001.cpp

@@ -0,0 +1,312 @@
+#include <iostream>
+#include <algorithm>
+#include <queue>
+#include <stack>
+#include <tuple>
+#include <utility>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1.5e5 + 5;
+
+int n, m, q, cnt, qr[N], lst[N];
+long long res, w[N];
+std::tuple<int, int, long long> edges[N];
+std::vector<long long> ans;
+
+class LinkCutTree {
+  private:
+    struct node {
+        size_t l, r, f;
+        int m;
+        bool rev;
+
+        node(const int &_p = 0, const size_t &_f = 0)
+            : l(0), r(0), f(_f), m(_p), rev(false) {}
+
+        size_t &child(unsigned x) {
+            return !x ? l : r;
+        }
+    } tr[N];
+
+    inline void pushup(size_t u) {
+        tr[u].m = u;
+
+        if (tr[u].l && w[tr[tr[u].l].m] > w[tr[u].m])
+            tr[u].m = tr[tr[u].l].m;
+
+        if (tr[u].r && w[tr[tr[u].r].m] > w[tr[u].m])
+            tr[u].m = tr[tr[u].r].m;
+    }
+
+    inline void pushdown(const size_t &u) {
+        if (!tr[u].rev) return;
+
+        std::swap(tr[u].l, tr[u].r);
+        tr[tr[u].l].rev = !tr[tr[u].l].rev;
+        tr[tr[u].r].rev = !tr[tr[u].r].rev;
+        tr[u].rev = false;
+    }
+
+    unsigned relation(const size_t &u) {
+        return u == tr[tr[u].f].l ? 0 : 1;
+    }
+
+    bool isRoot(const size_t &u) {
+        return tr[tr[u].f].l != u && tr[tr[u].f].r != u;
+    }
+
+    void rotate(size_t u) {
+        size_t p = tr[u].f;
+        unsigned x = relation(u);
+
+        if (!isRoot(p)) {
+            tr[tr[p].f].child(relation(p)) = u;
+        }
+        tr[u].f = tr[p].f;
+
+        if (tr[u].child(x ^ 1)) {
+            tr[tr[u].child(x ^ 1)].f = p;
+        }
+        tr[p].child(x) = tr[u].child(x ^ 1);
+
+        tr[u].child(x ^ 1) = p;
+        tr[p].f = u;
+
+        pushup(p);
+        pushup(u);
+    }
+
+    void splay(size_t u) {
+        std::stack<size_t> st;
+
+        size_t cur = u;
+        st.push(cur);
+        while (!isRoot(cur)) {
+            st.push(tr[cur].f);
+            cur = tr[cur].f;
+        }
+
+        while (!st.empty()) {
+            pushdown(st.top());
+            st.pop();
+        }
+
+        while (!isRoot(u)) {
+            if (isRoot(tr[u].f)) {
+                rotate(u);
+            } else if (relation(u) == relation(tr[u].f)) {
+                rotate(tr[u].f);
+                rotate(u);
+            } else {
+                rotate(u);
+                rotate(u);
+            }
+        }
+    }
+
+    void access(size_t u) {
+        for (size_t f = 0; u; u = tr[f = u].f) {
+            splay(u);
+            tr[u].r = f;
+            pushup(u);
+        }
+    }
+
+    void makeRoot(const size_t &u) {
+        access(u);
+        splay(u);
+        tr[u].rev = !tr[u].rev;
+    }
+
+    size_t findRoot(size_t u) {
+        access(u);
+        splay(u);
+
+        while (tr[u].l) {
+            u = tr[u].l;
+        }
+
+        return u;
+    }
+
+    void split(const size_t &x, const size_t &y) {
+        makeRoot(x);
+        access(y);
+        splay(y);
+    }
+
+  public:
+    bool check(int x, int y) {
+        return findRoot(x) == findRoot(y);
+    }
+
+    void set(int p, int v) {
+        tr[p].m = v;
+    }
+
+    unsigned query(int x, int y) {
+        split(x, y);
+
+        return tr[y].m;
+    }
+
+    void link(const int &x, const int &y) {
+        makeRoot(x);
+
+        if (findRoot(y) != x) {
+            tr[x].f = y;
+        }
+    }
+
+    void cut(int x, int y) {
+        split(x, y);
+
+        if (tr[y].l == x) {
+            tr[y].l = 0;
+            tr[x].f = 0;
+        }
+    }
+} lct;
+
+struct node {
+    int l, r;
+    std::vector<int> vec;
+} tr[N << 2];
+
+void build(int u, int l, int r) {
+    tr[u].l = l;
+    tr[u].r = r;
+
+    if (l == r) return;
+
+    int mid = (l + r) >> 1;
+
+    build(u << 1, l, mid);
+    build(u << 1 | 1, mid + 1, r);
+}
+
+void insert(int u, int l, int r, int id) {
+    if (l <= tr[u].l && tr[u].r <= r) {
+        tr[u].vec.emplace_back(id);
+
+        return;
+    }
+
+    int mid = (tr[u].l + tr[u].r) >> 1;
+
+    if (l <= mid) insert(u << 1, l, r, id);
+    if (r > mid) insert(u << 1 | 1, l, r, id);
+}
+
+void solve(int u) {
+    std::stack<std::pair<int, bool>> st;
+
+    for (int id : tr[u].vec) {
+        int x, y;
+        long long w;
+
+        std::tie(x, y, w) = edges[id];
+
+        if (lct.check(x, y)) {
+            int id2 = lct.query(x, y) - n,
+                x2, y2;
+            long long w2;
+
+            std::tie(x2, y2, w2) = edges[id2];
+
+            if (w2 <= w) continue;
+
+            lct.cut(x2, id2 + n);
+            lct.cut(id2 + n, y2);
+            st.emplace(id2, true);
+            res -= w2;
+        }
+
+        lct.link(x, id + n);
+        lct.link(id + n, y);
+        st.emplace(id, false);
+        res += w;
+    }
+
+    if (tr[u].l == tr[u].r) {
+        ans.emplace_back(res);
+    } else {
+        solve(u << 1);
+        solve(u << 1 | 1);
+    }
+
+    while (!st.empty()) {
+        int id;
+        bool type;
+
+        std::tie(id, type) = st.top();
+        st.pop();
+
+        int x, y;
+        long long w;
+
+        std::tie(x, y, w) = edges[id];
+
+        if (type) {
+            lct.link(x, id + n);
+            lct.link(id + n, y);
+            res += w;
+        } else {
+            lct.cut(x, id + n);
+            lct.cut(id + n, y);
+            res -= w;
+        }
+    }
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> m >> q;
+
+    for (int i = 1; i <= m; i++) {
+        int x, y;
+        long long z;
+
+        cin >> x >> y >> z;
+
+        w[n + (++cnt)] = z;
+        edges[cnt] = {x, y, z};
+        lst[i] = q + 1;
+    }
+
+    for (int i = 1; i <= q; i++) {
+        int k;
+        long long d;
+
+        cin >> k >> d;
+
+        qr[i] = k;
+        w[n + (++cnt)] = d;
+        edges[cnt] = {std::get<0>(edges[k]), std::get<1>(edges[k]), d};
+    }
+
+    build(1, 1, q);
+
+    for (int i = q; i; i--) {
+        insert(1, i, lst[qr[i]] - 1, m + i);
+        lst[qr[i]] = i;
+    }
+
+    for (int i = 1; i <= m; i++) {
+        if (lst[i] > 1) {
+            insert(1, 1, lst[i] - 1, i);
+        }
+    }
+
+    solve(1);
+
+    for (auto x : ans) cout << x << endl;
+
+    return 0;
+}