atcoder/abc185C

Author: xirc

atcoder/abc185/C/main.cpp

@@ -0,0 +1,66 @@
+#include <bits/stdc++.h>
+
+template<uint64_t MOD = std::numeric_limits<uint64_t>::max()>
+class CombinationPascal {
+    size_t N;
+    std::vector<std::vector<uint64_t>> comb;
+
+public:
+    // Time: O(N^2)
+    CombinationPascal(
+        size_t const N = 1000
+    )
+    {
+        build(N);
+    }
+    // Time: O(N^2)
+    void build(size_t const N) {
+        this->N = N;
+        comb.assign(N + 1, std::vector<uint64_t>(N + 1, 0));
+        comb[0][0] = 1;
+        for (size_t n = 1; n <= N; ++n) {
+            comb[n][0] = 1;
+            for (size_t k = 1; k <= N; ++k) {
+                comb[n][k] = (comb[n-1][k-1] + comb[n-1][k]) % MOD;
+            }
+        }
+    }
+    // nCk
+    // n = [0,N], k = [0,n]
+    // Time: O(1)
+    uint64_t C(size_t const n, size_t const k) const {
+        if (k > n) throw std::out_of_range("k");
+        if (n > N) throw std::out_of_range("n");
+        return comb[n][k];
+    }
+    // nHk
+    // H(n,k) = C(n+k-1,k)
+    // n = [0,N-k+1], k = [0,N]
+    // Time: O(1)
+    uint64_t H(size_t const n, size_t const k) const {
+        if (n == 0 && k == 0) return 1;
+        return C(n+k-1,k);
+    }
+    // Time: O(1)
+    size_t size() const {
+        return N;
+    }
+};
+
+using namespace std;
+using ll = int64_t;
+using ff = long double;
+
+int main() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(0); cout.tie(0);
+
+    int L;
+    cin >> L;
+
+    CombinationPascal<> solver(300);
+    ll ans = solver.H(12, L-12);
+    cout << ans << endl;
+
+    return 0;
+}