QOJ: Pico Park

Author: Macesuted

QOJ/9624.cpp

@@ -0,0 +1,82 @@
+/**
+ * @file 9624.cpp
+ * @author Macesuted ([email protected])
+ * @date 2024-11-13
+ *
+ * @copyright Copyright (c) 2024
+ *
+ */
+
+#include <bits/stdc++.h>
+using namespace std;
+
+#ifndef LOCAL
+#define endl '\n'
+#endif
+
+bool mem1;
+
+#define maxn 505
+#define mod 998244353
+
+string a;
+int64_t C[maxn][maxn], f[maxn][maxn];
+
+int Mod(int x) { return x >= mod ? x - mod : x; }
+
+void solve(void) {
+    int n;
+    cin >> n >> a, a = ' ' + a;
+
+    f[0][0] = 1;
+    for (int l = 1; l <= n; l++)
+        for (int r = l, cnt[2] = {0, 0}; r <= n; r++) {
+            if (a[r] == 'R' && cnt[0]) break;
+            cnt[a[r] == 'R']++;
+
+            int64_t coef = 0;
+
+            if (cnt[0] && cnt[1])
+                coef = (coef + (C[r - l - 1][cnt[0] - 1] + C[r - l - 1][cnt[1] - 1]) * (r - l)) % mod;
+            else if ((cnt[0] && l == 1) || (cnt[1] && r == n))
+                coef = Mod(coef + 1);
+            if (cnt[0] >= 2) coef = (coef + C[r - l - 1][cnt[0] - 2] * (r - l)) % mod;
+            if (cnt[1] >= 2) coef = (coef + C[r - l - 1][cnt[1] - 2] * (r - l)) % mod;
+
+            if (coef == 0) continue;
+
+            for (int k = 1; k <= r; k++) f[r][k] = (f[r][k] + f[l - 1][k - 1] * coef % mod * C[r][l - 1]) % mod;
+        }
+
+    for (int i = 0; i <= n; i++) {
+        for (int j = 0; j <= i; j++) cerr << f[i][j] << ' ';
+        cerr << endl;
+    }
+
+    for (int i = 1; i <= n; i++) cout << f[n][i] << ' ';
+    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
+
+    for (int i = 0; i < maxn; i++) {
+        C[i][0] = C[i][i] = 1;
+        for (int j = 1; j < i; j++) C[i][j] = Mod(C[i - 1][j - 1] + C[i - 1][j]);
+    }
+
+    int _ = 1;
+    while (_--) solve();
+
+#ifdef LOCAL
+    cerr << "Time Cost: " << clock() * 1000. / CLOCKS_PER_SEC << "MS" << endl;
+#endif
+    return 0;
+}