#include using namespace std; #define LOCAL #pragma region Macros typedef long long ll; #define ALL(x) (x).begin(),(x).end() const long long MOD=1000000007; // const long long MOD=998244353; const int INF=1e9+10; const long long IINF=1e18; const int dx[4]={1,0,-1,0},dy[4]={0,1,0,-1}; const char dir[4]={'D','R','U','L'}; template istream &operator>>(istream &is,vector &v){ for (T &x:v) is >> x; return is; } template ostream &operator<<(ostream &os,const vector &v){ for (int i=0;i ostream &operator<<(ostream &os,const pair &p){ os << '(' << p.first << ',' << p.second << ')'; return os; } template ostream &operator<<(ostream &os,const map &m){ os << '{'; for (auto itr=m.begin();itr!=m.end();++itr){ os << '(' << itr->first << ',' << itr->second << ')'; if (++itr!=m.end()) os << ','; --itr; } os << '}'; return os; } template ostream &operator<<(ostream &os,const set &s){ os << '{'; for (auto itr=s.begin();itr!=s.end();++itr){ os << *itr; if (++itr!=s.end()) os << ','; --itr; } os << '}'; return os; } void debug_out(){cerr << '\n';} template void debug_out(Head&& head,Tail&&... tail){ cerr << head; if (sizeof...(Tail)>0) cerr << ", "; debug_out(move(tail)...); } #ifdef LOCAL #define debug(...) cerr << " ";\ cerr << #__VA_ARGS__ << " :[" << __LINE__ << ":" << __FUNCTION__ << "]" << '\n';\ cerr << " ";\ debug_out(__VA_ARGS__) #else #define debug(...) 42 #endif template T gcd(T x,T y){return y!=0?gcd(y,x%y):x;} template T lcm(T x,T y){return x/gcd(x,y)*y;} template inline bool chmin(T1 &a,T2 b){ if (a>b){a=b; return true;} return false; } template inline bool chmax(T1 &a,T2 b){ if (a class modint{ using i64=int64_t; using u32=uint32_t; using u64=uint64_t; public: u32 v; constexpr modint(const i64 x=0) noexcept :v(x<0?mod-1-(-(x+1)%mod):x%mod){} constexpr u32 &value() noexcept {return v;} constexpr const u32 &value() const noexcept {return v;} constexpr modint operator+(const modint &rhs) const noexcept {return modint(*this)+=rhs;} constexpr modint operator-(const modint &rhs) const noexcept {return modint(*this)-=rhs;} constexpr modint operator*(const modint &rhs) const noexcept {return modint(*this)*=rhs;} constexpr modint operator/(const modint &rhs) const noexcept {return modint(*this)/=rhs;} constexpr modint &operator+=(const modint &rhs) noexcept { v+=rhs.v; if (v>=mod) v-=mod; return *this; } constexpr modint &operator-=(const modint &rhs) noexcept { if (v0){ if (exp&1) res*=self; self*=self; exp>>=1; } return res; } constexpr modint &operator++() noexcept {if (++v==mod) v=0; return *this;} constexpr modint &operator--() noexcept {if (v==0) v=mod; return --v,*this;} constexpr modint operator++(int) noexcept {modint t=*this; return ++*this,t;} constexpr modint operator--(int) noexcept {modint t=*this; return --*this,t;} template friend constexpr modint operator+(T x,modint y) noexcept {return modint(x)+y;} template friend constexpr modint operator-(T x,modint y) noexcept {return modint(x)-y;} template friend constexpr modint operator*(T x,modint y) noexcept {return modint(x)*y;} template friend constexpr modint operator/(T x,modint y) noexcept {return modint(x)/y;} constexpr bool operator==(const modint &rhs) const noexcept {return v==rhs.v;} constexpr bool operator!=(const modint &rhs) const noexcept {return v!=rhs.v;} constexpr bool operator!() const noexcept {return !v;} friend istream &operator>>(istream &s,modint &rhs) noexcept { i64 v; rhs=modint{(s>>v,v)}; return s; } friend ostream &operator<<(ostream &s,const modint &rhs) noexcept { return s< struct SegmentTree{ typedef function F; int n; F f; Monoid id; vector dat; SegmentTree(int n_,F f,Monoid id):f(f),id(id){init(n_);} void init(int n_){ n=1; while(n &v){ for (int i=0;i>=1) dat[k]=f(dat[k<<1|0],dat[k<<1|1]); } Monoid query(int a,int b){ if (a>=b) return id; Monoid vl=id,vr=id; for (int l=a+n,r=b+n;l>=1,r>>=1){ if (l&1) vl=f(vl,dat[l++]); if (r&1) vr=f(dat[--r],vr); } return f(vl,vr); } template int find_subtree(int k,const C &check,Monoid &M,bool type){ while(k int find_first(int a,const C &check){ Monoid L=id; if (a<=0){ if (check(f(L,dat[1]))) return find_subtree(1,check,L,false); return -1; } int b=n; for (int l=a+n,r=b+n;l>=1,r>>=1){ if (l&1){ Monoid nxt=f(L,dat[l]); if (check(nxt)) return find_subtree(l,check,L,false); L=nxt; ++l; } } return -1; } // max i s.t. f(seg[i],...,seg[b-2],seg[b-1]) satisfy "check" template int find_last(int b,const C &check){ Monoid R=id; if (b>=n){ if (check(f(dat[1],R))) return find_subtree(1,check,R,true); return -1; } int a=n; for (int l=a,r=b+n;l>=1,r>>=1){ if (r&1){ Monoid nxt=f(dat[--r],R); if (check(nxt)) return find_subtree(r,check,R,true); R=nxt; } } return -1; } Monoid operator[](int i){return dat[i+n];} }; using mint=modint; int main(){ cin.tie(0); ios::sync_with_stdio(false); int N; cin >> N; vector A(N); for (int i=0;i> A[i]; vector dp(N,INF),lis(N),pos(N); vector>> group(N+1); for (int i=0;i sz(N+1); for (int i=0;i<=N;++i){ sz[i]+=group[i].size(); if (i seg(N+1,[](mint a,mint b){return a+b;},0); seg.update(0,1); for (int i=0;i1){ int mid=(ub+lb)>>1; (group[lis[i]-1][mid].first0;--i){ if (!group[i].empty()){ ans=seg.query(sz[i-1],sz[i]); cout << ans << '\n'; return 0; } } }