upload some new code

FZOI/Tad的小蛋糕.cpp

@@ -0,0 +1,61 @@
+#include <bits/stdc++.h>
+#define int long long
+#define endl "\n"
+#define IMX LONG_LONG_MAX
+#define IMN LONG_LONG_MIN
+using namespace std;
+
+/* toothless. #17 */
+
+const int N = 1e7 + 10;
+const int M = 2e3 + 5;
+
+int n, m;
+int a[1000000];
+int qzh[1000000];
+int st[1000000][25];
+int lg[1000000];
+
+void init()
+{
+    lg[1] = 0;
+    for (int i = 2; i <= n; i++)
+    {
+        lg[i] = lg[i / 2] + 1;
+    }
+    for (int i = 1; i <= n; i++)
+    {
+        st[i][0] = qzh[i];
+    }
+    for (int k = 1; k <= lg[m]; k++)
+    {
+        for (int i = 1; i <= n; i++)
+        {
+            st[i][k] = max(st[i][k - 1], st[min(i + (1 << (k - 1)), n)][k - 1]);
+        }
+    }
+}  // ST表模板 -> 初始化
+int quary(int l, int r)
+{
+    int k = lg[r - l + 1];
+    return max(st[l][k], st[r - (1 << k) + 1][k]);
+}  // ST表模板 ->  求最大
+signed main()
+{
+    cin >> n >> m;
+    for (int i = 1; i <= n; i++)
+    {
+        cin >> a[i];
+        qzh[i] = qzh[i - 1] + a[i];
+    }
+    int maxl = -INT_MIN;
+    init();
+    for (int i = 1; i <= n; i++)
+    {
+        int r = min(i + m - 1, n);
+        int s = quary(i, r) - qzh[i - 1];
+        maxl = max(maxl, s);
+    }
+    cout << maxl;
+    return 0;
+}