#151. 【2020.12.1 NOIP模拟赛 T4】偷税计划

https://sjzezoj.com/submission/70023

S2OJ/151/151.cpp

@@ -0,0 +1,95 @@
+#include <iostream>
+#include <cstring>
+#include <utility>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e5 + 5,
+          M = 105;
+const int mod = 1e9 + 7;
+const int p[]{2, 3, 5, 7};
+
+int cnt, f[M][M][(1 << 4) + 5];
+std::vector<std::pair<int, int>> v[M], a[M];
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    for (int i = 2; i <= 100; i++) {
+        int x = i, s = 0;
+
+        for (int j = 0; j < 4; j++) {
+            while (x && x % p[j] == 0) {
+                x /= p[j];
+                s |= 1 << j;
+            }
+        }
+
+        v[x].emplace_back(i, s);
+    }
+
+    for (auto o : v[1]) {
+        a[++cnt].emplace_back(o);
+    }
+
+    for (int i = 2; i <= 100; i++) {
+        if (v[i].empty()) continue;
+
+        cnt++;
+
+        for (auto o : v[i]) {
+            a[cnt].emplace_back(o);
+        }
+    }
+
+    int t;
+
+    cin >> t;
+
+    while (t--) {
+        int n, m;
+
+        cin >> n >> m;
+
+        memset(f, 0x00, sizeof(f));
+
+        f[0][0][0] = 1;
+
+        for (int i = 1; i <= cnt; i++) {
+            for (int j = 0; j <= i; j++) {
+                for (int s = 0; s < 1 << 4; s++) {
+                    if (f[i - 1][j][s]) {
+                        f[i][j][s] = (static_cast<long long>(f[i][j][s]) + f[i - 1][j][s]) % mod;
+
+                        for (auto o : a[i]) {
+                            if (o.first > m) break;
+
+                            if (!(s & o.second)) {
+                                f[i][j + 1][s | o.second]
+                                    = (static_cast<long long>(f[i][j + 1][s | o.second])
+                                       + static_cast<long long>(f[i - 1][j][s]) * (n - j))
+                                    % mod;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        int ans = 0;
+
+        for (int j = 0; j <= cnt; j++) {
+            for (int s = 0; s < 1 << 4; s++) {
+                ans = (static_cast<long long>(ans) + f[cnt][j][s]) % mod;
+            }
+        }
+
+        cout << ans << endl;
+    }
+
+    return 0;
+}