牛客挑战赛44: https://ac.nowcoder.com/acm/contest/8051/F
冷知识:
#include <cstdio> #include <cstring> #include <cmath> #include <algorithm> #include <vector> #include <string> #include <map> #include <set> #include <cassert> #include<bits/stdc++.h> using namespace std; #define rep(i,a,n) for (int i=a;i<n;i++) #define per(i,a,n) for (int i=n-1;i>=a;i--) #define pb push_back #define mp make_pair #define all(x) (x).begin(),(x).end() #define fi first #define se second #define SZ(x) ((int)(x).size()) typedef vector<int> VI; typedef long long ll; typedef pair<int,int> PII; const ll mod=998244353; const int maxn=505; ll powmod(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;} // head typedef __int128 Int; long long _,n; namespace linear_seq { const long long N = 10010; ll res[N], base[N], _c[N], _md[N]; vector<long long> Md; void mul(ll *a, ll *b, long long k) { rep(i, 0, k + k) _c[i] = 0; rep(i, 0, k) if (a[i]) rep(j, 0, k) _c[i + j] = (_c[i + j] + a[i] * b[j]) % mod; for (long long i = k + k - 1; i >= k; i--) if (_c[i]) rep(j, 0, SZ(Md)) _c[i - k + Md[j]] = (_c[i - k + Md[j]] - _c[i] * _md[Md[j]]) % mod; rep(i, 0, k) a[i] = _c[i]; } long long solve(Int n, VI a, VI b) { // a 系数 b 初值 b[n+1]=a[0]*b[n]+... // printf("%d\n",SZ(b)); ll ans = 0; Int pnt = 0; Int k = SZ(a); assert(SZ(a) == SZ(b)); rep(i, 0, k) _md[k - 1 - i] = -a[i]; _md[k] = 1; Md.clear(); rep(i, 0, k) if (_md[i] != 0) Md.push_back(i); rep(i, 0, k) res[i] = base[i] = 0; res[0] = 1; while ((Int(1) << pnt) <= n) pnt++; for (Int p = pnt; p >= 0; p--) { mul(res, res, k); if ((n >> p) & 1) { for (long long i = k - 1; i >= 0; i--) res[i + 1] = res[i]; res[0] = 0; rep(j, 0, SZ(Md)) res[Md[j]] = (res[Md[j]] - res[k] * _md[Md[j]]) % mod; } } rep(i, 0, k) ans = (ans + res[i] * b[i]) % mod; if (ans < 0) ans += mod; return ans; } VI BM(VI s) { VI C(1, 1), B(1, 1); long long L = 0, m = 1, b = 1; rep(n, 0, SZ(s)) { ll d = 0; rep(i, 0, L + 1) d = (d + (ll)C[i] * s[n - i]) % mod; if (d == 0) ++m; else if (2 * L <= n) { VI T = C; ll c = mod - d * powmod(b, mod - 2) % mod; while (SZ(C) < SZ(B) + m) C.pb(0); rep(i, 0, SZ(B)) C[i + m] = (C[i + m] + c * B[i]) % mod; L = n + 1 - L; B = T; b = d; m = 1; } else { ll c = mod - d * powmod(b, mod - 2) % mod; while (SZ(C) < SZ(B) + m) C.pb(0); rep(i, 0, SZ(B)) C[i + m] = (C[i + m] + c * B[i]) % mod; ++m; } } return C; } long long gao(VI a, Int n) { VI c = BM(a); c.erase(c.begin()); rep(i, 0, SZ(c)) c[i] = (mod - c[i]) % mod; return solve(n, c, VI(a.begin(), a.begin() + SZ(c))); } }; Int a[maxn]; const int M=2; ll res[M][M],fu[M][M],co[M][M]; void cal(ll a[][M], ll b[][M]) { for (int i = 0; i < 2; i++) { for (int j = 0; j < 2; j++) { for (int k = 0; k < 2; k++) { fu[i][j] = (fu[i][j] + a[i][k] * b[k][j]) % mod; } } } for (int i = 0; i < 2; i++) { for (int j = 0; j < 2; j++) { a[i][j] = fu[i][j]; fu[i][j] = 0; } } } ll qpow( ll n ) { memset(res,0,sizeof(res)); res[0][0]=res[1][1]=1; memset(co,0,sizeof(co)); co[0][0]=co[0][1]=co[1][0]=1; while( n>0 ) { if( n&1 ) cal(res,co); cal(co,co); n>>=1; } return res[1][0]; } void read(Int &x) { x = 0; char c = getchar(); while (c < '0' || c > '9') c = getchar(); while (c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar(); } int main() { Int x,y,z,n; read(n);read(a[1]);read(a[2]);read(a[3]);read(x);read(y);read(z); //cin>>n>>a[1]>>a[2]>>a[3]>>x>>y>>z; for( int i=4;i<=500;i++ ) { a[i]=x*a[i-1]+y*a[i-2]%mod+z*a[i-3]; a[i]%=mod; } VI v; Int sum=0; for( int i=1;i<=500;i++ ) { sum=sum+a[i]*a[i]%mod; sum%=mod; v.push_back(sum); } printf("%lld\n",linear_seq::gao(v,n-1)); int q;scanf("%d",&q); while( q-- ) { int x;scanf("%d",&x); ll a=qpow(x),b=qpow(x+1); printf("%lld\n",a*b%mod); } }
2019牛客暑期多校训练营(第九场)A题 https://ac.nowcoder.com/acm/contest/889/A付费比赛贴一下题面
#include <bits/stdc++.h> using namespace std; #ifndef ONLINE_JUDGE #define debug(fmt, ...) fprintf(stderr, "[%s] " fmt "\n", __func__, ##__VA_ARGS__) #else #define debug(...) #endif // given first m items init[0..m-1] and coefficents trans[0..m-1] or // given first 2 *m items init[0..2m-1], it will compute trans[0..m-1] // for you. trans[0..m] should be given as that // init[m] = sum_{i=0}^{m-1} init[i] * trans[i] struct LinearRecurrence { using int64 = long long; using vec = std::vector<int64>; static void extand(vec& a, size_t d, int64 value = 0) { if (d <= a.size()) return; a.resize(d, value); } static vec BerlekampMassey(const vec& s, int64 mod) { std::function<int64(int64)> inverse = [&](int64 a) { return a == 1 ? 1 : (int64)(mod - mod / a) * inverse(mod % a) % mod; }; vec A = { 1 }, B = { 1 }; int64 b = s[0]; for (size_t i = 1, m = 1; i < s.size(); ++i, m++) { int64 d = 0; for (size_t j = 0; j < A.size(); ++j) { d += A[j] * s[i - j] % mod; } if (!(d %= mod)) continue; if (2 * (A.size() - 1) <= i) { auto temp = A; extand(A, B.si***t64 coef = d * inverse(b) % mod; for (size_t j = 0; j < B.size(); ++j) { A[j + m] -= coef * B[j] % mod; if (A[j + m] < 0) A[j + m] += mod; } B = temp, b = d, m = 0; } else { extand(A, B.si***t64 coef = d * inverse(b) % mod; for (size_t j = 0; j < B.size(); ++j) { A[j + m] -= coef * B[j] % mod; if (A[j + m] < 0) A[j + m] += mod; } } } return A; } static void exgcd(int64 a, int64 b, int64& g, int64& x, int64& y) { if (!b) x = 1, y = 0, g = a; else { exgcd(b, a % b, g, y, x); y -= x * (a / b); } } static int64 crt(const vec& c, const vec& m) { int n = c.size(); int64 M = 1, ans = 0; for (int i = 0; i < n; ++i) M *= m[i]; for (int i = 0; i < n; ++i) { int64 x, y, g, tm = M / m[i]; exgcd(tm, m[i], g, x, y); ans = (ans + tm * x * c[i] % M) % M; } return (ans + M) % M; } static vec ReedsSloane(const vec& s, int64 mod) { auto inverse = [](int64 a, int64 m) { int64 d, x, y; exgcd(a, m, d, x, y); return d == 1 ? (x % m + m) % m : -1; }; auto L = [](const vec& a, const vec& b) { int da = (a.size() > 1 || (a.size() == 1 && a[0])) ? a.size() - 1 : -1000; int db = (b.size() > 1 || (b.size() == 1 && b[0])) ? b.size() - 1 : -1000; return std::max(da, db + 1); }; auto prime_power = [&](const vec& s, int64 mod, int64 p, int64 e) { // linear feedback shift register mod p^e, p is prime std::vector<vec> a(e), b(e), an(e), bn(e), ao(e), bo(e); vec t(e), u(e), r(e), to(e, 1), uo(e), pw(e + 1); ; pw[0] = 1; for (int i = pw[0] = 1; i <= e; ++i) pw[i] = pw[i - 1] * p; for (int64 i = 0; i < e; ++i) { a[i] = { pw[i] }, an[i] = { pw[i] }; b[i] = { 0 }, bn[i] = { s[0] * pw[i] % mod }; t[i] = s[0] * pw[i] % mod; if (t[i] == 0) { t[i] = 1, u[i] = e; } else { for (u[i] = 0; t[i] % p == 0; t[i] /= p, ++u[i]) ; } } for (size_t k = 1; k < s.size(); ++k) { for (int g = 0; g < e; ++g) { if (L(an[g], bn[g]) > L(a[g], b[g])) { ao[g] = a[e - 1 - u[g]]; bo[g] = b[e - 1 - u[g]]; to[g] = t[e - 1 - u[g]]; uo[g] = u[e - 1 - u[g]]; r[g] = k - 1; } } a = an, b = bn; for (int o = 0; o < e; ++o) { int64 d = 0; for (size_t i = 0; i < a[o].size() && i <= k; ++i) { d = (d + a[o][i] * s[k - i]) % mod; } if (d == 0) { t[o] = 1, u[o] = e; } else { for (u[o] = 0, t[o] = d; t[o] % p == 0; t[o] /= p, ++u[o]) ; int g = e - 1 - u[o]; if (L(a[g], b[g]) == 0) { extand(bn[o], k + 1); bn[o][k] = (bn[o][k] + d) % mod; } else { int64 coef = t[o] * inverse(to[g], mod) % mod * pw[u[o] - uo[g]] % mod; int m = k - r[g]; extand(an[o], ao[g].size() + m); extand(bn[o], bo[g].size() + m); for (size_t i = 0; i < ao[g].size(); ++i) { an[o][i + m] -= coef * ao[g][i] % mod; if (an[o][i + m] < 0) an[o][i + m] += mod; } while (an[o].size() && an[o].back() == 0) an[o].pop_back(); for (size_t i = 0; i < bo[g].size(); ++i) { bn[o][i + m] -= coef * bo[g][i] % mod; if (bn[o][i + m] < 0) bn[o][i + m] -= mod; } while (bn[o].size() && bn[o].back() == 0) bn[o].pop_back(); } } } } return std::make_pair(an[0], bn[0]); }; std::vector<std::tuple<int64, int64, int>> fac; for (int64 i = 2; i * i <= mod; ++i) { if (mod % i == 0) { int64 cnt = 0, pw = 1; while (mod % i == 0) mod /= i, ++cnt, pw *= i; fac.emplace_back(pw, i, cnt); } } if (mod > 1) fac.emplace_back(mod, mod, 1); std::vector<vec> as; size_t n = 0; for (auto&& x : fac) { int64 mod, p, e; vec a, b; std::tie(mod, p, e) = x; auto ss = s; for (auto&& x : ss) x %= mod; std::tie(a, b) = prime_power(ss, mod, p, e); as.emplace_back(a); n = std::max(n, a.size()); } vec a(n), c(as.size()), m(as.size()); for (size_t i = 0; i < n; ++i) { for (size_t j = 0; j < as.size(); ++j) { m[j] = std::get<0>(fac[j]); c[j] = i < as[j].size() ? as[j][i] : 0; } a[i] = crt(c, m); } return a; } LinearRecurrence(const vec& s, const vec& c, int64 mod) : init(s), trans(c), mod(mod), m(s.size()) {} LinearRecurrence(const vec& s, int64 mod, bool is_prime = true) : mod(mod) { vec A; if (is_prime) A = BerlekampMassey(s, mod); else A = ReedsSloane(s, mod); if (A.empty()) A = { 0 }; m = A.size() - 1; trans.resize(m); for (int i = 0; i < m; ++i) { trans[i] = (mod - A[i + 1]) % mod; } std::reverse(trans.begin(), trans.end()); init = { s.begin(), s.begin() + m }; } int64 calc(int64 n) { if (mod == 1) return 0; if (n < m) return init[n]; vec v(m), u(m << 1); int msk = !!n; for (int64 m = n; m > 1; m >>= 1) msk <<= 1; v[0] = 1 % mod; for (int x = 0; msk; msk >>= 1, x <<= 1) { std::fill_n(u.begin(), m * 2, 0); x |= !!(n & msk); if (x < m) u[x] = 1 % mod; else { // can be optimized by fft/ntt for (int i = 0; i < m; ++i) { for (int j = 0, t = i + (x & 1); j < m; ++j, ++t) { u[t] = (u[t] + v[i] * v[j]) % mod; } } for (int i = m * 2 - 1; i >= m; --i) { for (int j = 0, t = i - m; j < m; ++j, ++t) { u[t] = (u[t] + trans[j] * u[i]) % mod; } } } v = { u.begin(), u.begin() + m }; } int64 ret = 0; for (int i = 0; i < m; ++i) { ret = (ret + v[i] * init[i]) % mod; } return ret; } vec init, trans; int64 mod; int m; }; const int mod = 1e9; typedef long long ll; ll Pow(ll a, ll n, ll mod) { ll t = 1; for (; n; n >>= 1, (a *= a) %= mod) if (n & 1) (t *= a) %= mod; return t; } int main() { int n, m; cin >> n >> m; std::vector<long long> f = { 0, 1 }; //预处理 2*m+5项 for (int i = 2; i < m * 2; i++) f.push_back((f[i - 1] + f[i - 2]) % mod); for (auto& t : f) t = Pow(t, m, mod); for (int i = 1; i < m * 2; i++) f[i] = (f[i - 1] + f[i]) % mod; LinearRecurrence solver(f, mod, false); printf("%lld\n", solver.calc(n)); }