upload some new code

FZOI/区间最大值.cpp

@@ -0,0 +1,51 @@
+#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[100050], dpmax[100050][100];
+int LOG[500005];
+void build()
+{
+    LOG[0] = -1;
+    for (int i = 1; i <= 500005; i++)
+        LOG[i] = LOG[i >> 1] + 1;
+    for (int i = 1; i <= n; i++) {
+        dpmax[i][0] = a[i];
+    }
+    int p = log2(n);
+    for (int k = 1; k <= p; k++) {
+        for (int s = 1; s + (1 << k) <= n + 1; s++) {
+            dpmax[s][k] = max(dpmax[s][k - 1], dpmax[s + (1 << (k - 1))][k - 1]);
+        }
+    }
+}
+int query(int l, int r)
+{
+    int k = LOG[r - l + 1];
+    int x = max(dpmax[l][k], dpmax[r - (1 << k) + 1][k]);
+    return x;
+}
+
+signed main()
+{
+    "toothless. #17";
+    cin >> n >> m;
+    for (int i = 1; i <= n; i++)
+        cin >> a[i];
+    build();
+    for (int i = 1; i <= m; i++) {
+        int l, r;
+        cin >> l >> r;
+        cout << query(l, r) << endl;
+    }
+    return 0;
+}