// Copyright © 2022 Youngmin Park. All rights reserved.
//#pragma GCC optimize("O3")
//#pragma GCC target("avx2")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;
using vpi = vector<pii>;
using pll = pair<ll, ll>;
using vl = vector<ll>;
using vpl = vector<pll>;
using ld = long double;
template <typename T, size_t SZ>
using ar = array<T, SZ>;
template <typename T>
using pqg = priority_queue<T, vector<T>, greater<T>>;
#define all(v) (v).begin(), (v).end()
#define pb push_back
#define sz(x) (int)(x).size()
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound
constexpr int INF = 1e9;
constexpr ll LINF = 1e18;
const ld PI = acos((ld)-1.0);
constexpr int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T>
constexpr bool ckmin(T &a, const T &b) { return b < a ? a = b, 1 : 0; }
template <typename T>
constexpr bool ckmax(T &a, const T &b) { return b > a ? a = b, 1 : 0; }
template <typename A, typename B>
ostream &operator<<(ostream &os, const pair<A, B> &p)
{
return os << '(' << p.first << ", " << p.second << ')';
}
template <typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type>
ostream &operator<<(ostream &os, const T_container &v)
{
os << '{';
string sep;
for (const T &x : v)
os << sep << x, sep = ", ";
return os << '}';
}
template <typename T>
ostream &operator<<(ostream &os, const deque<T> &v) {
os << vector<T>(all(v));
return os;
}
template <typename T, typename S, typename C>
ostream &operator<<(ostream &os, priority_queue<T, S, C> pq) {
vector<T> v;
while (sz(pq)) {
v.pb(pq.top());
pq.pop();
}
os << v;
return os;
}
void dbg_out()
{
cerr << "\033[0m" << endl;
}
template <typename Head, typename... Tail>
void dbg_out(Head H, Tail... T)
{
cerr << ' ' << H;
dbg_out(T...);
}
#ifdef LOCAL
#define dbg(...) cerr << "\033[1;35m" << __func__ << ':' << __LINE__ << " (" << #__VA_ARGS__ << "):\033[33m", dbg_out(__VA_ARGS__)
#else
#define dbg(...) 42
#endif
inline namespace RecursiveLambda
{
template <typename Fun>
struct y_combinator_result
{
Fun fun_;
template <typename T>
explicit y_combinator_result(T &&fun) : fun_(forward<T>(fun)) {}
template <typename... Args>
decltype(auto) operator()(Args &&...args)
{
return fun_(ref(*this), forward<Args>(args)...);
}
};
template <typename Fun>
decltype(auto) y_combinator(Fun &&fun)
{
return y_combinator_result<decay_t<Fun>>(forward<Fun>(fun));
}
};
inline namespace Range {
class ForwardRange {
int src, dst;
public:
explicit constexpr ForwardRange(const int l, const int r) : src(l), dst(r) {}
explicit constexpr ForwardRange(const int n) : src(0), dst(n) {}
constexpr ForwardRange begin() const { return *this; }
constexpr monostate end() const { return {}; }
constexpr bool operator!=(monostate) const { return src < dst; }
constexpr void operator++() const {}
constexpr int operator*() { return src++; }
};
class BackwardRange {
int src, dst;
public:
explicit constexpr BackwardRange(const int l, const int r) : src(r), dst(l) {}
explicit constexpr BackwardRange(const int n) : src(n), dst(0) {}
constexpr BackwardRange begin() const { return *this; }
constexpr monostate end() const { return {}; }
constexpr bool operator!=(monostate) const { return src > dst; }
constexpr void operator++() const {}
constexpr int operator*() { return --src; }
};
using rep = ForwardRange;
using per = BackwardRange;
};
/**
* Description: modular arithmetic operations
* Source:
* KACTL
* https://codeforces.com/blog/entry/63903
* https://codeforces.com/contest/1261/submission/65632855 (tourist)
* https://codeforces.com/contest/1264/submission/66344993 (ksun)
* also see https://github.com/ecnerwala/cp-book/blob/master/src/modnum.hpp (ecnerwal)
* Verification:
* https://open.kattis.com/problems/modulararithmetic
*/
template<int MOD, int RT> struct mint {
static const int mod = MOD;
static constexpr mint rt() { return RT; } // primitive root for FFT
int v; explicit operator int() const { return v; } // explicit -> don't silently convert to int
constexpr mint() { v = 0; }
constexpr mint(ll _v) noexcept { v = int((-MOD < _v && _v < MOD) ? _v : _v % MOD);
if (v < 0) v += MOD; }
constexpr bool operator==(const mint& o) const noexcept{
return v == o.v; }
constexpr friend bool operator!=(const mint& a, const mint& b) noexcept {
return !(a == b); }
constexpr friend bool operator<(const mint& a, const mint& b) noexcept {
return a.v < b.v; }
constexpr mint& operator+=(const mint& m) noexcept {
if ((v += m.v) >= MOD) v -= MOD;
return *this; }
constexpr mint& operator-=(const mint& m) noexcept {
if ((v -= m.v) < 0) v += MOD;
return *this; }
constexpr mint& operator*=(const mint& m) noexcept {
v = int((ll)v * m.v % MOD); return *this; }
constexpr mint& operator/=(const mint& m) noexcept { return (*this) *= inv(m); }
constexpr friend mint pow(mint a, ll p) noexcept {
mint ans = 1; assert(p >= 0);
for (; p; p /= 2, a *= a) if (p & 1) ans *= a;
return ans; }
constexpr friend mint inv(const mint& a) noexcept { assert(a.v != 0);
return pow(a, MOD - 2); }
constexpr mint operator-() const noexcept { return mint(-v); }
constexpr mint& operator++() noexcept { return *this += 1; }
constexpr mint& operator--() noexcept { return *this -= 1; }
constexpr friend mint operator+(mint a, const mint& b) noexcept { return a += b; }
constexpr friend mint operator-(mint a, const mint& b) noexcept { return a -= b; }
constexpr friend mint operator*(mint a, const mint& b) noexcept { return a *= b; }
constexpr friend mint operator/(mint a, const mint& b) noexcept { return a /= b; }
friend istream& operator>>(istream& is, mint& o){
ll v; is >> v; o = mint(v); return is; }
friend ostream& operator<<(ostream& os, const mint& o){
os << o.v; return os; }
};
template <typename M>
struct Combination {
static const int mod = M::mod;
vector<M> fact, invFact, inv;
Combination(int N) noexcept {
fact.resize(N + 1), invFact.resize(N + 1), inv.resize(N + 1);
fact[0] = 1;
for (int i = 1; i <= N; i++) {
fact[i] = fact[i - 1] * i;
}
inv[1] = 1;
for (int i = 2; i <= N; ++i) {
inv[i] = mod - (mod / i) * inv[mod % i];
}
invFact[0] = invFact[1] = 1;
for (int i = 2; i <= N; ++i){
invFact[i] = invFact[i - 1] * inv[i];
}
}
constexpr M binom(int n, int k) const noexcept {
if (n < k || n < 0) return 0;
return fact[n] * invFact[k] * invFact[n - k];
}
};
constexpr int MOD = 1e9 + 7; // 998244353;
using Mint = mint<MOD,5>; // 5 is primitive root for both common mods
using Combo = Combination<Mint>;
using vmi = vector<Mint>;
Combo C(300000);
void solve()
{
int n, k;
cin >> n >> k;
vi a(n);
vector<Mint> ans(n, 1);
for (auto &e : a) cin >> e;
stack<int> stckL, stckR;
vector<vpi> todoL(200001), todoR(200001);
for (int i : rep(1, n)) {
while (sz(stckL) && a[stckL.top()] > a[i - 1]) {
todoL[a[stckL.top()]].pb({i, -1});
stckL.pop();
}
stckL.push(i - 1);
todoL[a[i - 1]].pb({i, 1});
}
for (int i : per(n - 1)) {
while (sz(stckR) && a[stckR.top()] > a[i + 1]) {
todoR[a[stckR.top()]].pb({i, -1});
stckR.pop();
}
stckR.push(i + 1);
todoR[a[i + 1]].pb({i, 1});
}
for (int i : rep(1, n + 1)) {
auto &u = todoL[i];
auto &v = todoR[i];
int L{}, R{};
for (auto &[id, fl] : v) R += fl, id = id + 1, fl = -fl;
reverse(all(v));
int p{}, q{};
while (p != sz(u) || q != sz(v)) {
if (p < sz(u) && q < sz(v) && u[p].fi == v[q].fi) {
ans[u[p].fi] /= C.binom(L + R, L);
L += u[p].se;
R += v[q].se;
ans[u[p].fi] *= C.binom(L + R, L);
p++, q++;
}else{
if (p == sz(u) || (q != sz(v) && v[q].fi < u[p].fi)) {
ans[v[q].fi] /= C.binom(L + R, L);
R += v[q].se;
ans[v[q].fi] *= C.binom(L + R, L);
q++;
}else{
ans[u[p].fi] /= C.binom(L + R, L);
L += u[p].se;
ans[u[p].fi] *= C.binom(L + R, L);
p++;
}
}
}
}
for (int i : rep(1, n)) ans[i] *= ans[i - 1];
for (int i : rep(k)) {
int t;
cin >> t;
cout << ans[t - 1] << '\n';
}
}
int main()
{
cin.tie(0)->sync_with_stdio(0);
cin.exceptions(cin.failbit);
int testcase = 1;
// cin >> testcase;
while (testcase--)
{
solve();
}
#ifdef LOCAL
cerr << "Time elapsed: " << 1.0 * (double)clock() / CLOCKS_PER_SEC << " s.\n";
#endif
}
Compilation message
zarulje.cpp: In function 'void solve()':
zarulje.cpp:275:11: warning: unused variable 'i' [-Wunused-variable]
275 | for (int i : rep(k)) {
| ^
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
13 ms |
13140 KB |
Output is correct |
| 2 |
Correct |
14 ms |
13268 KB |
Output is correct |
| 3 |
Correct |
13 ms |
13392 KB |
Output is correct |
| 4 |
Correct |
14 ms |
13396 KB |
Output is correct |
| 5 |
Correct |
15 ms |
13304 KB |
Output is correct |
| 6 |
Correct |
15 ms |
13396 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
100 ms |
18448 KB |
Output is correct |
| 2 |
Correct |
165 ms |
23020 KB |
Output is correct |
| 3 |
Correct |
206 ms |
23108 KB |
Output is correct |
| 4 |
Correct |
204 ms |
24324 KB |
Output is correct |
| 5 |
Correct |
207 ms |
25836 KB |
Output is correct |
| 6 |
Correct |
263 ms |
26316 KB |
Output is correct |
| 7 |
Correct |
251 ms |
26744 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
13 ms |
13140 KB |
Output is correct |
| 2 |
Correct |
14 ms |
13268 KB |
Output is correct |
| 3 |
Correct |
13 ms |
13392 KB |
Output is correct |
| 4 |
Correct |
14 ms |
13396 KB |
Output is correct |
| 5 |
Correct |
15 ms |
13304 KB |
Output is correct |
| 6 |
Correct |
15 ms |
13396 KB |
Output is correct |
| 7 |
Correct |
100 ms |
18448 KB |
Output is correct |
| 8 |
Correct |
165 ms |
23020 KB |
Output is correct |
| 9 |
Correct |
206 ms |
23108 KB |
Output is correct |
| 10 |
Correct |
204 ms |
24324 KB |
Output is correct |
| 11 |
Correct |
207 ms |
25836 KB |
Output is correct |
| 12 |
Correct |
263 ms |
26316 KB |
Output is correct |
| 13 |
Correct |
251 ms |
26744 KB |
Output is correct |
| 14 |
Correct |
23 ms |
13908 KB |
Output is correct |
| 15 |
Correct |
121 ms |
20300 KB |
Output is correct |
| 16 |
Correct |
205 ms |
26200 KB |
Output is correct |
| 17 |
Correct |
202 ms |
24308 KB |
Output is correct |
| 18 |
Correct |
227 ms |
27404 KB |
Output is correct |
| 19 |
Correct |
237 ms |
27168 KB |
Output is correct |
| 20 |
Correct |
277 ms |
27852 KB |
Output is correct |
| 21 |
Correct |
312 ms |
28284 KB |
Output is correct |
