/*constexpr ll mod = 998244353; @\hl{NTT only}@ constexpr ll root = 3;*/ using cplx = complex; //void fft(vector &a, bool inverse = 0) { @\hl{NTT, xor, or, and}@ void fft(vector& a, bool inverse = 0) { int n = sz(a); for (int i = 0, j = 1; j < n - 1; ++j) { for (int k = n >> 1; k > (i ^= k); k >>= 1); if (j < i) swap(a[i], a[j]); } static vector ws(2, 1); for (static int k = 2; k < n; k *= 2) { ws.resize(n); cplx w = polar(1.0, acos(-1.0) / k); for (int i=k; i<2*k; i++) ws[i] = ws[i/2] * (i % 2 ? w : 1); } for (int s = 1; s < n; s *= 2) { /*ll ws = powMod(root, (mod - 1) / s >> 1, mod); @\hl{NTT only}@ if (inverse) ws = powMod(ws, mod - 2, mod);*/ for (int j = 0; j < n; j += 2 * s) { //ll w = 1; @\hl{NTT only}@ for (int k = 0; k < s; k++) { /*ll u = a[j + k], t = a[j + s + k] * w; @\hl{NTT only}@ t %= mod; a[j + k] = (u + t) % mod; a[j + s + k] = (u - t + mod) % mod; w = (w * ws) % mod;*/ /*ll u = a[j + k], t = a[j + s + k]; @\hl{xor only}@ a[j + k] = u + t; a[j + s + k] = u - t;*/ /*if (!inverse) { @\hl{or only}@ a[j + k] = u + t; a[j + s + k] = u; } else { a[j + k] = t; a[j + s + k] = u - t; }*/ /*if (!inverse) { @\hl{and only}@ a[j + k] = t; a[j + s + k] = u + t; } else { a[j + k] = t - u; a[j + s + k] = u; }*/ cplx u = a[j + k], t = a[j + s + k]; t *= (inverse ? conj(ws[s + k]) : ws[s + k]); a[j + k] = u + t; a[j + s + k] = u - t; if (inverse) a[j + k] /= 2, a[j + s + k] /= 2; }}} /*if (inverse) { @\hl{NTT only}@ ll div = powMod(n, mod - 2, mod); for (ll i = 0; i < n; i++) { a[i] = (a[i] * div) % mod; }}*/ /*if (inverse) { @\hl{xor only}@ for (ll i = 0; i < n; i++) { a[i] /= n; }}*/ }