vector poly_inv(const vector& a, int n) { vector q = {powMod(a[0], mod-2, mod)}; for (int len = 1; len < n; len *= 2){ vector a2 = a, q2 = q; a2.resize(2*len), q2.resize(2*len); ntt(q2); for (int _ : {0, 1}) { ntt(a2); for (int i = 0; i < 2*len; i++) a2[i] = a2[i]*q2[i] % mod; ntt(a2, true); for (int i = 0; i < len; i++) a2[i] = 0; } for (int i = len; i < min(n, 2*len); i++) { q.push_back((mod - a2[i]) % mod); }} return q; } vector poly_deriv(vector a) { for (int i = 1; i < sz(a); i++) a[i-1] = a[i] * i % mod; a.pop_back(); return a; } vector poly_integr(vector a) { if (a.empty()) return {0}; a.push_back(a.back() * powMod(sz(a), mod-2, mod) % mod); for (int i = sz(a)-2; i > 0; i--) a[i] = a[i-1] * powMod(i, mod-2, mod) % mod; a[0] = 0; return a; } vector poly_log(vector a, int n) { a = mul(poly_deriv(a), poly_inv(a, n)); a.resize(n-1); a = poly_integr(a); return a; } vector poly_exp(vector a, int n) { vector q = {1}; for (int len = 1; len < n; len *= 2) { vector p = poly_log(q, 2*len); for (int i = 0; i < 2*len; i++) p[i] = (mod - p[i] + (i < sz(a) ? a[i] : 0)) % mod; vector q2 = q; q2.resize(2*len); ntt(p), ntt(q2); for (int i = 0; i < 2*len; i++) p[i] = p[i] * q2[i] % mod; ntt(p, true); for (int i = len; i < min(n, 2*len); i++) q.push_back(p[i]); } return q; }