LibreOJ: 2093

「ZJOI2016」线段树

Author: Macesuted

LibreOJ/2093.cpp

@@ -0,0 +1,76 @@
+/**
+ * @file 2093.cpp
+ * @author Macesuted ([email protected])
+ * @date 2022-06-01
+ *
+ * @copyright Copyright (c) 2022
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+bool mem1;
+
+#define maxn 405
+#define mod 1000000007
+
+int a[maxn];
+int64_t f[2][maxn][maxn], g[maxn][maxn], h[maxn][maxn];
+
+int64_t Pow(int64_t a, int64_t x) {
+    int64_t ans = 1;
+    while (x) {
+        if (x & 1) ans = ans * a % mod;
+        a = a * a % mod, x >>= 1;
+    }
+    return ans;
+}
+
+void solve(void) {
+    int n, m;
+    cin >> n >> m;
+    for (int i = 1; i <= n; i++) cin >> a[i];
+    a[0] = a[n + 1] = 0x3f3f3f3f;
+    for (int i = 1; i <= n; i++)
+        for (int j = i, maxVal = a[i]; j <= n; maxVal = max(maxVal, a[++j]))
+            if (i != 1 || j != n) f[0][i][j] = (f[0][i][j] + max(0, min(a[i - 1], a[j + 1]) - maxVal)) % mod;
+    auto F = [&](int l, int r) { return (l - 1) * l / 2 + (r - l + 1) * (r - l + 2) / 2 + (n - r) * (n - r + 1) / 2; };
+    for (int k = 1; k <= m; k++) {
+        bool t = k & 1;
+        for (int i = 1; i <= n; i++)
+            for (int j = i; j <= n; j++) g[i][j] = (g[i - 1][j] + f[!t][i][j] * (i - 1)) % mod;
+        for (int i = 1; i <= n; i++)
+            for (int j = n; j >= i; j--) h[i][j] = (h[i][j + 1] + f[!t][i][j] * (n - j)) % mod;
+        for (int i = 1; i <= n; i++)
+            for (int j = i; j <= n; j++) f[t][i][j] = (f[!t][i][j] * F(i, j) + g[i - 1][j] + h[i][j + 1]) % mod;
+    }
+    int maxVal = 0;
+    for (int i = 1; i <= n; i++) maxVal = max(maxVal, a[i]);
+    int tot = maxVal * Pow(n * (n + 1) / 2, m) % mod;
+    for (int i = 1; i <= n; i++) {
+        int64_t ans = tot;
+        for (int l = 1; l <= i; l++)
+            for (int r = i; r <= n; r++) ans = (ans + mod - f[m & 1][l][r]) % mod;
+        cout << ans << ' ';
+    }
+    cout << 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;
+    while (_--) solve();
+
+#ifdef LOCAL
+    cerr << "Time Cost: " << clock() * 1000. / CLOCKS_PER_SEC << "MS" << endl;
+#endif
+    return 0;
+}