#include #include #include using namespace std; typedef long long ll; const int mod = 1000000007; template struct Seg{ private: vector node; int n; F f; T def; public: Seg(int siz, T d, F f) : def(d), f(f) { n = 1; while(n < siz) n *= 2; node.resize(2*n-1, def); } Seg(vector v, T d, F f) : def(d), f(f){ n = 1; while(n < v.size()) n *= 2; node.resize(2*n-1); for(int i = 0; i < v.size(); i++) node[n-1+i] = v[i]; for(int i = n-2; i >= 0; i--) node[i] = f(node[2*i+1], node[2*i+2]); } void update(int x, T val){ x += n-1; node[x] = val; /* ! */ while(x){ x = (x-1)/2; node[x] = f(node[2*x+1], node[2*x+2]); } } T query(int a, int b){ int L = a+n-1, R = b+n-1; T ret = def; while(L < R){ if((R&1) == 0) ret = f(ret, node[--R]); if((L&1) == 0) ret = f(ret, node[L++]); L >>= 1, R >>= 1; } return ret; } }; struct Box{ int length, count; }; int main(){ int n; cin >> n; vector> vp; for(int i = 0; i < n; i++){ int x; cin >> x; vp.push_back({x, -i}); } sort(vp.begin(), vp.end()); vector a(n); for(int i = 0; i < n; i++){ a[-vp[i].second] = i; } auto f = [](Box a, Box b){ if(a.length < b.length){ return b; }else if(a.length > b.length){ return a; }else if(a.length == b.length){ (a.count += b.count) %= mod; return a; } return a; }; Seg argmax(n+1, {0,0}, f); argmax.update(0, {0,1}); for(int i = 0; i < n; i++){ int pos = -vp[i].second+1; Box now = argmax.query(0, pos); now.length++; argmax.update(pos, now); } cout << argmax.query(1, n+1).count << endl; return 0; }