HDOJ: 7517

cats 的快乐 CF 刷题

HDOJ/7517.cpp

@@ -0,0 +1,118 @@
+/**
+ * @file 7517.cpp
+ * @author Macesuted ([email protected])
+ * @date 2024-08-12
+ *
+ * @copyright Copyright (c) 2024
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+#define maxn 200005
+
+typedef tuple<int64_t, int64_t, int64_t, int> tllli;
+
+class FenwickTree {
+   private:
+    vector<int64_t> tree;
+    int n;
+
+   public:
+    void resize(int _n) { return tree.resize((n = _n) + 1, 0); }
+    void add(int p, int64_t v) {
+        for (int i = p; i <= n; i += i & -i) tree[i] += v;
+        return;
+    }
+    int64_t sum(int p) {
+        int64_t sum = 0;
+        for (int i = p; i; i -= i & -i) sum += tree[i];
+        return sum;
+    }
+};
+
+tllli a[maxn];
+int pos[maxn];
+vector<tllli> F[maxn][2];
+
+bool cmp(tllli a, tllli b) {
+    if (!get<0>(b) && !get<1>(b)) return false;
+    if (!get<0>(a) && !get<1>(a)) return true;
+    return get<0>(a) * get<1>(b) > get<1>(a) * get<0>(b);
+}
+
+void solve(void) {
+    int n;
+    cin >> n;
+    for (int i = 1; i <= n; i++) cin >> get<0>(a[i]) >> get<1>(a[i]), get<2>(a[i]) = get<0>(a[i]) * get<1>(a[i]);
+    for (int i = 0; i <= n + 1; i++) F[i][0].clear(), F[i][1].clear();
+    vector<tllli> cac;
+    stack<tllli> S;
+    for (int i = 1; i <= n; i++) {
+        tllli cur = a[i];
+        while (!S.empty() && cmp(cur, S.top())) {
+            cur = {get<0>(cur) + get<0>(S.top()), get<1>(cur) + get<1>(S.top()),
+                   get<2>(cur) + get<2>(S.top()) + get<0>(S.top()) * get<1>(cur), 0};
+            F[i][1].push_back(S.top()), S.pop();
+        }
+        get<3>(cur) = cac.size(), S.push(cur), F[i][0].push_back(cur), cac.push_back(cur);
+    }
+    while (!S.empty()) F[n + 1][1].push_back(S.top()), S.pop();
+    for (int i = n; i; i--) {
+        tllli cur = a[i];
+        while (!S.empty() && cmp(cur, S.top())) {
+            cur = {get<0>(cur) + get<0>(S.top()), get<1>(cur) + get<1>(S.top()),
+                   get<2>(cur) + get<2>(S.top()) + get<0>(S.top()) * get<1>(cur), 0};
+            F[i][0].push_back(S.top()), S.pop();
+        }
+        get<3>(cur) = cac.size(), S.push(cur), F[i][1].push_back(cur), cac.push_back(cur);
+    }
+    while (!S.empty()) F[0][0].push_back(S.top()), S.pop();
+
+    sort(cac.begin(), cac.end(), cmp);
+    for (int i = 0; i < (int)cac.size(); i++) pos[get<3>(cac[i])] = i + 1;
+
+    FenwickTree Fa, Fb;
+    Fa.resize(cac.size()), Fb.resize(cac.size());
+    int64_t ans = 0, tot = 0;
+    for (int i = 0; i <= n + 1; i++) {
+        for (auto v : F[i][0]) {
+            int p = pos[get<3>(v)];
+            tot += Fa.sum(p - 1) * get<1>(v) + (Fb.sum(cac.size()) - Fb.sum(p)) * get<0>(v) + get<2>(v);
+            Fa.add(p, get<0>(v)), Fb.add(p, get<1>(v));
+        }
+        for (auto v : F[i][1]) {
+            int p = pos[get<3>(v)];
+            Fa.add(p, -get<0>(v)), Fb.add(p, -get<1>(v));
+            tot -= Fa.sum(p - 1) * get<1>(v) + (Fb.sum(cac.size()) - Fb.sum(p)) * get<0>(v) + get<2>(v);
+        }
+        ans = max(ans, tot);
+    }
+    cout << ans << endl;
+    return;
+}
+
+bool mem2;
+
+int main() {
+    ios::sync_with_stdio(false), cin.tie(nullptr);
+#ifdef LOCAL
+    cerr << "Memory Cost: " << abs(&mem1 - &mem2) / 1024. / 1024. << "MB" << endl;
+#endif
+
+    int _ = 1;
+    cin >> _;
+    while (_--) solve();
+
+#ifdef LOCAL
+    cerr << "Time Cost: " << clock() * 1000. / CLOCKS_PER_SEC << "MS" << endl;
+#endif
+    return 0;
+}