Sun, 04 Aug 2019 14:04:44 +0800

nowcoder884/C.cpp

@@ -18,6 +18,7 @@ struct SegTree
     struct Node
     {
         ll sum, lmx, lmn, rmx, rmn;
+        void init(const int x) { sum = x, lmx = x, lmn = x, rmx = x, rmn = x; }
     } N[sz << 2];
     void merge(Node &c, Node &l, Node &r)
     {
@@ -27,17 +28,17 @@ struct SegTree
         c.lmx = max(l.lmx, l.sum + r.lmx);
         c.rmx = max(r.rmx, r.sum + l.rmx);
     }
-    void update(int k) { merge(N[k], N[L(k)], N[R(k)]); }
     void build(int k, int l, int r, int *a)
     {
-        if (l == r - 1) return void(N[k].mn = N[k].mx = 1);
+        if (l == r - 1) return N[k].init(a[l]);
         int m = avg(l, r);
         build(L(k), l, m, a);
         build(R(k), m, r, a);
-        update(k);
+        merge(N[k], N[L(k)], N[R(k)]);
     }
     Node query(int k, int l, int r, int x, int y)
     {
+        if (x >= y) return {};
         if (x <= l && r <= y) return N[k];
         int m = avg(l, r);
         if (y <= m) return query(L(k), l, m, x, y);
@@ -68,35 +69,28 @@ int main()
     scanf("%d", &n);
     for (int i = 1; i <= n; i++) read(a[i]);
     for (int i = 1; i <= n; i++) read(b[i]);
+    a[0] = a[n + 1] = -inf;
     v.clear(), v.push_back(0);
     for (int i = 1; i <= n; i++)
     {
-        while (a[v.back()] > a[i]) v.pop_back();
-        l[i] = v.back();
-        v.push_back(i);
+        while (a[v.back()] >= a[i]) v.pop_back();
+        l[i] = v.back(), v.push_back(i);
     }
     v.clear(), v.push_back(n + 1);
     for (int i = n; i >= 1; i--)
     {
-        while (a[v.back()] > a[i]) v.pop_back();
-        r[i] = v.back();
-        v.push_back(i);
+        while (a[v.back()] >= a[i]) v.pop_back();
+        r[i] = v.back(), v.push_back(i);
     }
-    /*for (int i = 1; i <= n; i++) printf("%2d ", a[i]);
-    putchar('\n');
-    for (int i = 1; i <= n; i++) printf("%2d ", l[i]);
-    putchar('\n');
-    for (int i = 1; i <= n; i++) printf("%2d ", r[i]);
-    putchar('\n');*/
     st.build(1, 0, n, b + 1);
     long long ans = 0;
     for (int i = 1; i <= n; i++)
     {
-        int lb = l[i] + 1, rb = r[i];
-        auto resl = st.query(1, 0, n, lb, i);
-        auto resr = st.query(1, 0, n, i, rb);
-        ans = max(ans, a[i] < 0 ? a[i] * (resl.rmn + a[i] + resr.lmn) :
-                                  a[i] * (resl.rmx + a[i] + resr.lmx));
+        auto resl = st.query(1, 0, n, l[i], i - 1);
+        auto resr = st.query(1, 0, n, i, r[i] - 1);
+        ans = max(ans, a[i] < 0 ? a[i] * (resl.rmn + b[i] + resr.lmn) :
+                                  a[i] * (resl.rmx + b[i] + resr.lmx));
     }
+    printf("%lld", ans);
     return 0;
 }

nowcoder885/.vscode/launch.json

@@ -1,20 +0,0 @@
-{
-    // 使用 IntelliSense 了解相关属性。 
-    // 悬停以查看现有属性的描述。
-    // 欲了解更多信息，请访问: https://go.microsoft.com/fwlink/?linkid=830387
-    "version": "0.2.0",
-    "configurations": [
-        {
-            "name": "cl.exe build and debug active file",
-            "type": "cppvsdbg",
-            "request": "launch",
-            "program": "${fileDirname}\\${fileBasenameNoExtension}.exe",
-            "args": [],
-            "stopAtEntry": false,
-            "cwd": "${workspaceFolder}",
-            "environment": [],
-            "externalConsole": false,
-            "preLaunchTask": "cl.exe build active file"
-        }
-    ]
-}

nowcoder885/.vscode/tasks.json

@@ -1,18 +0,0 @@
-{
-    "tasks": [
-        {
-            "type": "shell",
-            "label": "cl.exe build active file",
-            "command": "cl.exe",
-            "args": [
-                "/ID:\\PortableApps\\MSYS2\\mingw64\\include\\c++\\9.1.0\\x86_64-w64-mingw32",
-                "/Zi",
-                "/EHsc",
-                "/Fe:",
-                "${fileDirname}\\${fileBasenameNoExtension}.exe",
-                "${file}"
-            ]
-        }
-    ],
-    "version": "2.0.0"
-}