1 files changed, 65 insertions, 0 deletions
diff --git a/content/math/polynomial.cpp b/content/math/polynomial.cpp
new file mode 100644
index 0000000..44f6207
--- /dev/null
+++ b/content/math/polynomial.cpp
@@ -0,0 +1,65 @@
+struct poly {
+	vector<ll> data;
+
+	poly(int deg = 0) : data(max(1, deg)) {}
+	poly(initializer_list<ll> _data) : data(_data) {}
+
+	int size() const {return sz(data);}
+
+	void trim() {
+		for (ll& x : data) x = (x % mod + mod) % mod;
+		while (size() > 1 && data.back() == 0) data.pop_back();
+	}
+
+	ll& operator[](int x) {return data[x];}
+	const ll& operator[](int x) const {return data[x];}
+
+	ll operator()(int x) const {
+		ll res = 0;
+		for (int i = size() - 1; i >= 0; i--)
+			res = (res * x + data[i]) % mod;
+		return res % mod;
+	}
+
+	poly& operator+=(const poly& o) {
+		if (size() < o.size()) data.resize(o.size());
+		for (int i = 0; i < o.size(); i++)
+			data[i] = (data[i] + o[i]) % mod;
+		return *this;
+	}
+
+	poly operator*(const poly& o) const {
+		poly res(size() + o.size() - 1);
+		for (int i = 0; i < size(); i++) {
+			for (int j = 0; j < o.size(); j++) {
+				res[i + j] += (data[i] * o[j]) % mod;
+		}}
+		res.trim();
+		return res;
+	}
+
+	//return p(x+a)
+	poly operator<<(ll a) const {
+		poly res(size());
+		for (int i = size() - 1; i >= 0; i--) {
+			for (int j = size() - i - 1; j >= 1; j--)
+				res[j] = (res[j] * a + res[j - 1]) % mod;
+			res[0] = (res[0] * a + res[i]) % mod;
+		}
+		return res;
+	}
+
+	pair<poly, poly> divmod(const poly& d) const {
+		int i = size() - d.size();
+		poly s(i + 1), r = *this;
+		ll inv = multInv(d.data.back(), mod);
+		for (; i >= 0; i--) {
+			s[i] = (r.data.back() * inv) % mod;
+			r.data.pop_back();
+			for (int j = 0; i + j < r.size(); j++) {
+				r[i + j] = (r.data[i + j] - s[i] * d[j]) % mod;
+		}}
+		s.trim(); r.trim();
+		return {s, r};
+	}
+};