#include //#include //#include using namespace std; #define DEBUG(x) cerr<<#x<<": "< #define vl vector #define vii vector< vector > #define vll vector< vector > #define vs vector #define pii pair #define pis pair #define psi pair #define pll pair template pair operator+(const pair &s, const pair &t) { return pair(s.first + t.first, s.second + t.second); } template pair operator-(const pair &s, const pair &t) { return pair(s.first - t.first, s.second - t.second); } template ostream& operator<<(ostream& os, pair p) { os << "(" << p.first << ", " << p.second << ")"; return os; } #define X first #define Y second #define rep(i,n) for(int i=0;i<(n);i++) #define rep1(i,n) for(int i=1;i<=(n);i++) #define rrep(i,n) for(int i=(n)-1;i>=0;i--) #define rrep1(i,n) for(int i=(n);i>0;i--) #define REP(i,a,b) for(int i=a;i bool chmax(T &a, const T &b) { if (a bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; } #define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end()); const ll inf = 1000000001; const ll INF = (ll)1e18 + 1; const long double pi = 3.1415926535897932384626433832795028841971L; #define Sp(p) cout< class SegmentTree { public: using F = function; int n; vector dat; T e; // �P�ʌ� F query_func; F update_func; SegmentTree(){} SegmentTree(vector a, F query_func, F update_func, T e) :n(a.size()), query_func(query_func), update_func(update_func), e(e) { dat.resize(4 * n); init(0, 0, n, a); } void init(int k, int l, int r, vector &a) { if (r - l == 1) { dat[k] = a[l]; } else { int lch = 2 * k + 1, rch = 2 * k + 2; init(lch, l, (l + r) / 2, a); init(rch, (l + r) / 2, r, a); dat[k] = query_func(dat[lch], dat[rch]); } } //k�Ԗڂ̒l��a�ɕύX void update(int k, T a, int v, int l, int r) { if (r - l == 1) { dat[v] = update_func(dat[v], a); } else { if (k < (l + r) / 2) update(k, a, 2 * v + 1, l, (l + r) / 2); else { update(k, a, 2 * v + 2, (l + r) / 2, r); } dat[v] = query_func(dat[v * 2 + 1], dat[v * 2 + 2]); } } //[a,b)�̍ŏ��l�����߂� //���̂ق��̈����͌v�Z�̊ȒP�̂��߂̈��� //k�͐ړ_�̔ԍ�,l,r�͂��̐ړ_��[l,r)�ɑΉ����Ă��邱�Ƃ�\�� //�]���āA�O�����query(a,b,0,0,n)�Ƃ��Ă�� T query(int a, int b, int k, int l, int r) { if (r <= a || b <= l) { return e; } if (a <= l && r <= b) { return dat[k]; } else { T ul = query(a, b, k * 2 + 1, l, (l + r) / 2); T ur = query(a, b, k * 2 + 2, (l + r) / 2, r); return query_func(ul, ur); } } // �����𖞂����ĉE��T�� int find(int a, int b, int k, int l, int r, int x) { // �����𒼂� if (dat[k] < x || r <= a || b <= l) return -1; if (l + 1 == r) { // �����𒼂� if (dat[k] >= x) return l; else return -1; } int rv = find(a, b, 2 * k + 2, (l + r) / 2, r, x); if (rv != -1) return rv; return find(a, b, 2 * k + 1, l, (l + r) / 2, x); } }; signed main() { int n; cin >> n; vi a(n); rep (i, n) cin >> a[i]; vi len(n); vi dp(n + 1, inf); dp[0] = -inf; rep (i, n) { auto itr = lower_bound(all(dp), a[i]); int idx = itr - dp.begin(); len[i] = idx; dp[idx] = a[i]; } int ma; rrep (i, n + 1) { if (dp[i] != inf) { ma = i; break; } } vii len2idx(ma + 1); len2idx[0].push_back(-1); rep (i, n) { len2idx[len[i]].push_back(i); } //DEBUG_MAT(len2idx); auto f = [](int a, int b) {return (a + b) % MOD;}; auto g = [](int a, int b) {return (a + b) % MOD;}; vector> segs(ma + 1); segs[0] = SegmentTree(vi(1), f, g, 0); segs[0].update(0, 1, 0, 0, segs[0].n); rep1 (i, ma) { segs[i] = SegmentTree(vi(len2idx[i].size()), f, g, 0); } vector> b(n); rep (i, n) { b[i] = {a[i] - i * 1e-9, i}; } sort(all(b)); rep (i, n) { int idx = b[i].second; int le = len[idx]; int r = lower_bound(all(len2idx[le - 1]), idx) - len2idx[le - 1].begin(); int sum = segs[le - 1].query(0, r, 0, 0, segs[le - 1].n); int r2 = lower_bound(all(len2idx[le]), idx) - len2idx[le].begin(); segs[le].update(r2, sum, 0, 0, segs[le].n); } cout << segs[ma].query(0, segs[ma].n, 0, 0, segs[ma].n) % MOD << endl; }