結果
問題 |
No.3257 +|+
|
ユーザー |
|
提出日時 | 2025-09-06 09:32:30 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 189 ms / 3,000 ms |
コード長 | 15,006 bytes |
コンパイル時間 | 2,987 ms |
コンパイル使用メモリ | 213,904 KB |
実行使用メモリ | 130,688 KB |
最終ジャッジ日時 | 2025-09-06 09:32:40 |
合計ジャッジ時間 | 9,562 ms |
ジャッジサーバーID (参考情報) |
judge3 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 33 |
ソースコード
#include <bits/stdc++.h> using namespace std; //入力が必ず-mod<a<modの時. template<const int mod> struct modint{ //mod変更が不可能. public: long long v = 0; static void setmod(int m){} //飾り. static constexpr long long getmod(){return mod;} modint(){v = 0;} modint(int a){v = a<0?a+mod:a;} modint(long long a){v = a<0?a+mod:a;} modint(unsigned int a){v = a;} modint(unsigned long long a){v = a;} long long val()const{return v;} modint &operator=(const modint &b) = default; modint operator+()const{return (*this);} modint operator-()const{return modint(0)-(*this);} modint operator+(const modint b)const{return modint(v)+=b;} modint operator-(const modint b)const{return modint(v)-=b;} modint operator*(const modint b)const{return modint(v)*=b;} modint operator/(const modint b)const{return modint(v)/=b;} modint operator+=(const modint b){ v += b.v; if(v >= mod) v -= mod; return *this; } modint operator-=(const modint b){ v -= b.v; if(v < 0) v += mod; return *this; } modint operator*=(const modint b){v = v*b.v%mod; return *this;} modint operator/=(modint b){ //b!=0 mod素数が必須. if(b == 0) assert(false); int left = mod-2; while(left){if(left&1) *this *= b; b *= b; left >>= 1;} return *this; } modint operator++(){*this += 1; return *this;} modint operator--(){*this -= 1; return *this;} modint operator++(int){*this += 1; return *this;} modint operator--(int){*this -= 1; return *this;} bool operator==(const modint b)const{return v == b.v;} bool operator!=(const modint b)const{return v != b.v;} bool operator>(const modint b)const{return v > b.v;} bool operator>=(const modint b)const{return v >= b.v;} bool operator<(const modint b)const{return v < b.v;} bool operator<=(const modint b)const{return v <= b.v;} modint pow(long long n)const{ modint ret = 1,p = v; if(n < 0) p = p.inv(),n = -n; while(n){ if(n&1) ret *= p; p *= p; n >>= 1; } return ret; } modint inv()const{return modint(1)/v;} //素数mod必須. }; using mint = modint<998244353>; const long long mod = 998244353; namespace to_fold{ __int128_t safemod(__int128_t a,long long m){a %= m; if(a < 0) a += m; return a;} pair<long long,long long> invgcd(long long a,long long b){ //return {gcd(a,b),x} (xa≡g(mod b)) a = safemod(a,b); if(a == 0) return {b,0}; long long x = 0,y = 1,memob = b; while(a){ long long q = b/a; b -= a*q; swap(x,y); y -= q*x; swap(a,b); } if(x < 0) x += memob/b; return {b,x}; } template<long long mod> long long Garner(const vector<long long> &A,const vector<long long> &M){ __int128_t mulM = 1,x = A.at(0)%M.at(0); //Mの要素のペア互いに素必須. for(int i=1; i<A.size(); i++){ //assert(gcd(mulM,M.at(i-1)) == 1); mulM *= M.at(i-1); //2乗がオーバーフローする時__int128_t long long t = safemod((A.at(i)-x)*invgcd(mulM,M.at(i)).second,M.at(i)); x += t*mulM; } return x%mod; } int countzero(unsigned long long x){ if(x == 0) return 64; else return __popcount((x&-x)-1); } template<typename mint> struct fftinfo{ static bool First; static mint g,sum_e[30],sum_ie[30]; //sum_e[i]=Π[j=0~i-1]ies[j] * es[i],sum_ie[i]=Π[i=0~j-1]es[j] * ies[i]. static mint divpow2[30]; //div[i] = 1/(2^i). static mint Zeta[30]; fftinfo(){ if(!First) return; First = false; const long long mod = mint::getmod(); if(mod == 998244353) g = 3; else if(mod == 754974721) g = 11; else if(mod == 167772161) g = 3; else if(mod == 469762049) g = 3; else assert(false); //現状RE. mint es[30],ies[30]; //es[i]^(2^(2+i))=1. int cnt2 = countzero(mod-1); mint e = g.pow((mod-1)>>cnt2),ie = e.inv(); for(int i=cnt2; i>=2; i--){ //e^(2^i)=1; es[i-2] = e,e *= e; ies[i-2] = ie,ie *= ie; } mint rot = 1; for(int i=0; i<=cnt2-2; i++) sum_e[i] = es[i]*rot,rot *= ies[i]; rot = 1; for(int i=0; i<=cnt2-2; i++) sum_ie[i] = ies[i]*rot,rot *= es[i]; mint div2n = 1,div2 = mint(1)/2; for(int i=0; i<30; i++) divpow2[i] = div2n,div2n *= div2; for(int i=0; i<=cnt2; i++) Zeta[i] = g.pow((mod-1)/(2<<i)); } }; template<typename mint> bool fftinfo<mint>::First=true; template<typename mint> mint fftinfo<mint>::g; template<typename mint> mint fftinfo<mint>::sum_e[30]; template<typename mint> mint fftinfo<mint>::sum_ie[30]; template<typename mint> mint fftinfo<mint>::divpow2[30]; template<typename mint> mint fftinfo<mint>::Zeta[30]; template<typename mint> void NTT(vector<mint> &A){ //ACLを超参考にしてる. int n = A.size(); assert((n&-n) == n); fftinfo<mint> info; int h = countzero(n); for(int ph=1; ph<=h; ph++){ int w = 1<<(ph-1),p = 1<<(h-ph); mint rot = 1; for(int s=0; s<w; s++){ int offset = s<<(h-ph+1); for(int i=0; i<p; i++){ mint l = A.at(i+offset),r = A.at(i+offset+p)*rot; A.at(i+offset) = l+r; A.at(i+offset+p) = l-r; } rot *= info.sum_e[countzero(~(unsigned int)(s))]; } } } template<typename mint> void INTT(vector<mint> &A){ int n = A.size(); assert((n&-n) == n); fftinfo<mint> info; const unsigned int mod = mint::getmod(); int h = countzero(n); for(int ph=h; ph>0; ph--){ int w = 1<<(ph-1),p = 1<<(h-ph); mint irot = 1; for(int s=0; s<w; s++){ int offset = s<<(h-ph+1); for(int i=0; i<p; i++){ mint l = A.at(i+offset),r = A.at(i+offset+p); A.at(i+offset) = l+r; A.at(i+offset+p) = ((unsigned long long)(mod+(unsigned int)l.v-(unsigned int)r.v)*irot.v)%mod; } irot *= info.sum_ie[countzero(~(unsigned int)(s))]; } } mint divn = info.divpow2[h]; for(auto &a : A) a *= divn; } template<typename mint> vector<mint> convolution(vector<mint> A,vector<mint> B){ //mintじゃないのを突っ込まないように!!!. int siza = A.size(),sizb = B.size(),sizc = siza+sizb-1,N = 1; if(siza == 0 || sizb == 0) return {}; if(min(siza,sizb) <= 60){ //naive. vector<mint> ret(sizc); if(siza >= sizb){for(int i=0; i<siza; i++) for(int k=0; k<sizb; k++) ret.at(i+k) += A.at(i)*B.at(k);} else{for(int i=0; i<sizb; i++) for(int k=0; k<siza; k++) ret.at(i+k) += B.at(i)*A.at(k);} return ret; } while(N < sizc) N <<= 1; A.resize(N),B.resize(N); NTT(A); NTT(B); for(int i=0; i<N; i++) A.at(i) *= B.at(i); INTT(A); A.resize(sizc); return A; } template<typename T> vector<long long> convolution_ll(const vector<T> &A,const vector<T> &B){ //long longに収まる範囲. int siza = A.size(),sizb = B.size(),sizc = siza+sizb-1; if(siza == 0 || sizb == 0) return {}; vector<long long> ret(sizc); if(min(siza,sizb) <= 200){ //naive 200はやばい?. if(siza >= sizb){for(int i=0; i<siza; i++) for(int k=0; k<sizb; k++) ret.at(i+k) += (long long)A.at(i)*B.at(k);} else{for(int i=0; i<sizb; i++) for(int k=0; k<siza; k++) ret.at(i+k) += (long long)B.at(i)*A.at(k);} return ret; } const unsigned long long mod1 = 754974721,mod2 = 167772161,mod3 = 469762049; //const unsigned long long m1m2 = mod1*mod2,m2m3 = mod2*mod3,m3m1 = mod3*mod1,m1m2m3 = mod1*mod2*mod3; const unsigned long long m1m2 = 126663740442542081,m2m3 = 78812994116517889,m3m1 = 354658471880163329,m1m2m3 = 560135205046714369; //const unsigned long long i1 = invgcd(m2m3,mod1).second,i2 = invgcd(m3m1,mod2).second,i3 = invgcd(m1m2,mod3).second; const unsigned long long i1 = 190329765,i2 = 58587104,i3 = 187290749; assert(sizc <= (1<<24)); using mint1 = modint<mod1>; using mint2 = modint<mod2>; using mint3 = modint<mod3>; vector<mint1> a1(siza),b1(sizb); vector<mint2> a2(siza),b2(sizb); vector<mint3> a3(siza),b3(sizb); for(int i=0; i<siza; i++) a1.at(i) = A.at(i)%mod1; for(int i=0; i<sizb; i++) b1.at(i) = B.at(i)%mod1; vector<mint1> C1 = convolution(a1,b1); for(int i=0; i<siza; i++) a2.at(i) = A.at(i)%mod2; for(int i=0; i<sizb; i++) b2.at(i) = B.at(i)%mod2; vector<mint2> C2 = convolution(a2,b2); for(int i=0; i<siza; i++) a3.at(i) = A.at(i)%mod3; for(int i=0; i<sizb; i++) b3.at(i) = B.at(i)%mod3; vector<mint3> C3 = convolution(a3,b3); vector<unsigned long long> offset = {0,0,m1m2m3,2*m1m2m3,3*m1m2m3}; for(int i=0; i<sizc; i++){ unsigned long long x = 0; x += (C1.at(i).v*i1)%mod1*m2m3; x += (C2.at(i).v*i2)%mod2*m3m1; x += (C3.at(i).v*i3)%mod3*m1m2; long long diff = C1.at(i).v-((long long)x+(long long)mod1)%mod1; if(diff < 0) diff += mod1; x -= offset.at(diff%5); ret.at(i) = x; } return ret; } template<typename mint> vector<mint> convolution_llmod(const vector<mint> &A,const vector<mint> &B){ int siza = A.size(),sizb = B.size(),sizc = siza+sizb-1; if(siza == 0 || sizb == 0) return {}; vector<mint> ret(sizc); if(min(siza,sizb) <= 200){ for(int i=0; i<siza; i++) for(int k=0; k<sizb; k++) ret.at(i+k) += A.at(i)*B.at(k); return ret; } const long long mod1 = 754974721,mod2 = 167772161,mod3 = 469762049; assert(sizc <= (1<<24)); using mint1 = modint<mod1>; using mint2 = modint<mod2>; using mint3 = modint<mod3>; vector<mint1> a1(siza),b1(sizb); vector<mint2> a2(siza),b2(sizb); vector<mint3> a3(siza),b3(sizb); for(int i=0; i<siza; i++) a1.at(i) = A.at(i).v%mod1; for(int i=0; i<sizb; i++) b1.at(i) = B.at(i).v%mod1; vector<mint1> C1 = convolution(a1,b1); for(int i=0; i<siza; i++) a2.at(i) = A.at(i).v%mod2; for(int i=0; i<sizb; i++) b2.at(i) = B.at(i).v%mod2; vector<mint2> C2 = convolution(a2,b2); for(int i=0; i<siza; i++) a3.at(i) = A.at(i).v%mod3; for(int i=0; i<sizb; i++) b3.at(i) = B.at(i).v%mod3; vector<mint3> C3 = convolution(a3,b3); for(int i=0; i<sizc; i++){ vector<long long> A = {C1.at(i).v,C2.at(i).v,C3.at(i).v}; vector<long long> M = {mod1,mod2,mod3}; ret.at(i) = Garner<mint::getmod()>(A,M); } return ret; } template<typename T> vector<__int128_t> convolution_i128(const vector<T> &A,const vector<T> &B){ //10^25に収まる範囲. int siza = A.size(),sizb = B.size(),sizc = siza+sizb-1; if(siza == 0 || sizb == 0) return {}; vector<__int128_t> ret(sizc); if(min(siza,sizb) <= 200){ //naive 200はやばい?. if(siza >= sizb){for(int i=0; i<siza; i++) for(int k=0; k<sizb; k++) ret.at(i+k) += (long long)A.at(i)*B.at(k);} else{for(int i=0; i<sizb; i++) for(int k=0; k<siza; k++) ret.at(i+k) += (long long)B.at(i)*A.at(k);} return ret; } const int mod1 = 167772161,mod2 = 469762049,mod3 = 754974721; //const int m12 = invgcd(mod1,mod2).second,m13 = invgcd(mod1,mod3).second,m23 = invgcd(mod2,mod3).second,m13m23 = (long long)m13*m23%mod3; const int m12 = 104391568,m13 = 323560596,m23 = 399692502,m13m23 = 190329765; //const long long w1 = mod1,w2 = w1*mod2; const long long w1 = 167772161,w2 = 78812994116517889; assert(sizc <= (1<<24)); using mint1 = modint<mod1>; using mint2 = modint<mod2>; using mint3 = modint<mod3>; vector<mint1> a1(siza),b1(sizb); vector<mint2> a2(siza),b2(sizb); vector<mint3> a3(siza),b3(sizb); for(int i=0; i<siza; i++) a1.at(i) = A.at(i)%mod1; for(int i=0; i<sizb; i++) b1.at(i) = B.at(i)%mod1; vector<mint1> C1 = convolution(a1,b1); for(int i=0; i<siza; i++) a2.at(i) = A.at(i)%mod2; for(int i=0; i<sizb; i++) b2.at(i) = B.at(i)%mod2; vector<mint2> C2 = convolution(a2,b2); for(int i=0; i<siza; i++) a3.at(i) = A.at(i)%mod3; for(int i=0; i<sizb; i++) b3.at(i) = B.at(i)%mod3; vector<mint3> C3 = convolution(a3,b3); for(int i=0; i<sizc; i++){ long long v2 = C2.at(i).v,v3 = C3.at(i).v; long long a = C1.at(i).v; long long b = (v2+mod2-a)*m12 %mod2; long long c= ((v3+mod3-a)*m13m23+(mod3-b)*m23) %mod3; ret.at(i) = a+b*w1+(__int128_t)c*w2; } return ret; } vector<int> convolution_int(const vector<int> &A,const vector<int> &B){ //intに収まる範囲. if(A.size() == 0 || B.size() == 0) return {}; vector<int> ret; if(min(A.size(),B.size()) <= 60){ ret.resize(A.size()+B.size()-1); for(int i=0; i<A.size(); i++) for(int k=0; k<B.size(); k++) ret.at(i+k) += A.at(i)*B.at(k); } else{ using mint1 = modint<998244353>; vector<mint1> X(A.size()),Y(B.size()),Z; for(int i=0; i<A.size(); i++) X.at(i) = A.at(i); for(int i=0; i<B.size(); i++) Y.at(i) = B.at(i); Z = convolution(X,Y); ret.resize(Z.size()); for(int i=0; i<Z.size(); i++) ret.at(i) = Z.at(i).v; } return ret; } template<typename mint> void NTTdoubling(vector<mint> &A){ //NTTの原理を忘れているため何やってるのか意味が分からない NTT-friendly専用. //INTT->resize(2倍)->NTTの代わりにcopy->INTT->謎の操作->NTT->push sizeが小さい時は効率悪いらしいよ. int n = A.size(); fftinfo<mint> info; vector<mint> B = A; INTT(B); mint rot = 1,zeta = info.Zeta[countzero(n)]; for(auto &v : B) v *= rot,rot *= zeta; NTT(B); A.reserve(n<<1); for(auto &v : B) A.push_back(v); } bool isNTTfriendly(long long mod){ if(mod == 998244353 || mod == 754974721 || mod == 16777216 || mod == 469762049) return true; return false; //現状false 原子根求める機能を追加してから. int have2 = countzero(mod-1); return have2 >= 20;//とりあえず2^20でokとする; } } using namespace to_fold; int main() { ios_base::sync_with_stdio(false); cin.tie(nullptr); int N; cin >> N; vector<int> A(N); for(auto &a : A) cin >> a; long long answer = 0; int n = min(5000,N); for(int i=0; i<n; i++) for(int k=i+1; k<n; k++) if((A.at(i)+A.at(k))%(i+k+2) == 0) answer++; if(n != N){ vector Cs(80,vector<int>(400000)); for(int i=1; i<=n; i++){ int a = A.at(i-1)+200000; for(int k=1; k<80; k++){ a -= i; if(a < 0) break; Cs.at(k)[a]++; } } for(int i=n+1; i<=N; i++){ int a = A.at(i-1); for(int k=1; ; k++){ a -= i; if(a < -200000) break; answer += Cs.at(k)[-a+200000]; Cs.at(k)[a+200000]++; } } } cout << answer << endl; }