結果

問題 No.1827 最長部分スーパーリッチ門松列列
ユーザー nok0nok0
提出日時 2022-01-28 22:25:28
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
WA  
実行時間 -
コード長 17,786 bytes
コンパイル時間 4,147 ms
コンパイル使用メモリ 208,400 KB
実行使用メモリ 5,096 KB
最終ジャッジ日時 2023-08-28 20:31:30
合計ジャッジ時間 7,788 ms
ジャッジサーバーID
（参考情報） 		judge11 / judge12
このコードへのチャレンジ
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 2 ms
4,380 KB
testcase_01 AC 2 ms
4,380 KB
testcase_02 WA -
testcase_03 WA -
testcase_04 WA -
testcase_05 WA -
testcase_06 WA -
testcase_07 AC 121 ms
4,828 KB
testcase_08 AC 121 ms
4,868 KB
testcase_09 AC 121 ms
4,916 KB
testcase_10 AC 120 ms
4,852 KB
testcase_11 WA -
testcase_12 WA -
testcase_13 WA -
testcase_14 AC 118 ms
4,804 KB
testcase_15 AC 119 ms
4,828 KB
testcase_16 AC 117 ms
4,808 KB
testcase_17 AC 436 ms
4,800 KB
testcase_18 WA -
testcase_19 WA -
testcase_20 WA -
testcase_21 WA -
testcase_22 AC 278 ms
4,852 KB
testcase_23 AC 279 ms
5,076 KB
testcase_24 AC 277 ms
4,792 KB
権限があれば一括ダウンロードができます

ソースコード

diff # 

#line 1 "f.cpp"
/**
 *	author: nok0
 *	created: 2022.01.28 22:03:00
**/

#line 1 "/Users/nok0/Documents/Programming/nok0/cfmulti.hpp"
#include <bits/stdc++.h>
using namespace std;

#pragma region Macros
// rep macro
#define foa(v, a) for(auto &v : a)
#define REPname(a, b, c, d, e, ...) e
#define REP(...) REPname(__VA_ARGS__, REP3, REP2, REP1, REP0)(__VA_ARGS__)
#define REP0(x) for(int i = 0; i < (x); ++i)
#define REP1(i, x) for(int i = 0; i < (x); ++i)
#define REP2(i, l, r) for(int i = (l); i < (r); ++i)
#define REP3(i, l, r, c) for(int i = (l); i < (r); i += (c))
#define REPSname(a, b, c, ...) c
#define REPS(...) REPSname(__VA_ARGS__, REPS1, REPS0)(__VA_ARGS__)
#define REPS0(x) for(int i = 1; i <= (x); ++i)
#define REPS1(i, x) for(int i = 1; i <= (x); ++i)
#define RREPname(a, b, c, d, e, ...) e
#define RREP(...) RREPname(__VA_ARGS__, RREP3, RREP2, RREP1, RREP0)(__VA_ARGS__)
#define RREP0(x) for(int i = (x)-1; i >= 0; --i)
#define RREP1(i, x) for(int i = (x)-1; i >= 0; --i)
#define RREP2(i, r, l) for(int i = (r)-1; i >= (l); --i)
#define RREP3(i, r, l, c) for(int i = (r)-1; i >= (l); i -= (c))
#define RREPSname(a, b, c, ...) c
#define RREPS(...) RREPSname(__VA_ARGS__, RREPS1, RREPS0)(__VA_ARGS__)
#define RREPS0(x) for(int i = (x); i >= 1; --i)
#define RREPS1(i, x) for(int i = (x); i >= 1; --i)

// name macro
#define pb push_back
#define eb emplace_back
#define SZ(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define popcnt(x) __builtin_popcountll(x)
template <class T = int>
using V = std::vector<T>;
template <class T = int>
using VV = std::vector<std::vector<T>>;
template <class T>
using pqup = std::priority_queue<T, std::vector<T>, std::greater<T>>;
using ll = long long;
using ld = long double;
using int128 = __int128_t;
using pii = std::pair<int, int>;
using pll = std::pair<long long, long long>;

// input macro
template <class T, class U>
std::istream &operator>>(std::istream &is, std::pair<T, U> &p) {
	is >> p.first >> p.second;
	return is;
}
template <class T>
std::istream &operator>>(std::istream &is, std::vector<T> &v) {
	for(T &i : v) is >> i;
	return is;
}
std::istream &operator>>(std::istream &is, __int128_t &a) {
	std::string s;
	is >> s;
	__int128_t ret = 0;
	for(int i = 0; i < s.length(); i++)
		if('0' <= s[i] and s[i] <= '9')
			ret = 10 * ret + s[i] - '0';
	a = ret * (s[0] == '-' ? -1 : 1);
	return is;
}
namespace scanner {
void scan(int &a) { std::cin >> a; }
void scan(long long &a) { std::cin >> a; }
void scan(std::string &a) { std::cin >> a; }
void scan(char &a) { std::cin >> a; }
void scan(char a[]) { std::scanf("%s", a); }
void scan(double &a) { std::cin >> a; }
void scan(long double &a) { std::cin >> a; }
template <class T, class U>
void scan(std::pair<T, U> &p) { std::cin >> p; }
template <class T>
void scan(std::vector<T> &a) { std::cin >> a; }
void INPUT() {}
template <class Head, class... Tail>
void INPUT(Head &head, Tail &...tail) {
	scan(head);
	INPUT(tail...);
}
}  // namespace scanner
#define VEC(type, name, size)     \
	std::vector<type> name(size); \
	scanner::INPUT(name)
#define VVEC(type, name, h, w)                                    \
	std::vector<std::vector<type>> name(h, std::vector<type>(w)); \
	scanner::INPUT(name)
#define INT(...)     \
	int __VA_ARGS__; \
	scanner::INPUT(__VA_ARGS__)
#define LL(...)            \
	long long __VA_ARGS__; \
	scanner::INPUT(__VA_ARGS__)
#define STR(...)             \
	std::string __VA_ARGS__; \
	scanner::INPUT(__VA_ARGS__)
#define CHAR(...)     \
	char __VA_ARGS__; \
	scanner::INPUT(__VA_ARGS__)
#define DOUBLE(...)     \
	double __VA_ARGS__; \
	scanner::INPUT(__VA_ARGS__)
#define LD(...)              \
	long double __VA_ARGS__; \
	scanner::INPUT(__VA_ARGS__)

// output-macro
template <class T, class U>
std::ostream &operator<<(std::ostream &os, const std::pair<T, U> &p) {
	os << p.first << " " << p.second;
	return os;
}
template <class T>
std::ostream &operator<<(std::ostream &os, const std::vector<T> &a) {
	for(int i = 0; i < int(a.size()); ++i) {
		if(i) os << " ";
		os << a[i];
	}
	return os;
}
std::ostream &operator<<(std::ostream &dest, __int128_t &value) {
	std::ostream::sentry s(dest);
	if(s) {
		__uint128_t tmp = value < 0 ? -value : value;
		char buffer[128];
		char *d = std::end(buffer);
		do {
			--d;
			*d = "0123456789"[tmp % 10];
			tmp /= 10;
		} while(tmp != 0);
		if(value < 0) {
			--d;
			*d = '-';
		}
		int len = std::end(buffer) - d;
		if(dest.rdbuf()->sputn(d, len) != len) {
			dest.setstate(std::ios_base::badbit);
		}
	}
	return dest;
}
template <class T>
void print(const T a) { std::cout << a << '\n'; }
template <class Head, class... Tail>
void print(Head H, Tail... T) {
	std::cout << H << ' ';
	print(T...);
}
template <class T>
void printel(const T a) { std::cout << a << '\n'; }
template <class T>
void printel(const std::vector<T> &a) {
	for(const auto &v : a)
		std::cout << v << '\n';
}
template <class Head, class... Tail>
void printel(Head H, Tail... T) {
	std::cout << H << '\n';
	printel(T...);
}
void Yes(const bool b = true) { std::cout << (b ? "Yes\n" : "No\n"); }
void No() { std::cout << "No\n"; }
void YES(const bool b = true) { std::cout << (b ? "YES\n" : "NO\n"); }
void NO() { std::cout << "NO\n"; }
void err(const bool b = true) {
	if(b) {
		std::cout << "-1\n", exit(0);
	}
}

//debug macro
namespace debugger {
template <class T>
void view(const std::vector<T> &a) {
	std::cerr << "{ ";
	for(const auto &v : a) {
		std::cerr << v << ", ";
	}
	std::cerr << "\b\b }";
}
template <class T>
void view(const std::vector<std::vector<T>> &a) {
	std::cerr << "{\n";
	for(const auto &v : a) {
		std::cerr << "\t";
		view(v);
		std::cerr << "\n";
	}
	std::cerr << "}";
}
template <class T, class U>
void view(const std::vector<std::pair<T, U>> &a) {
	std::cerr << "{\n";
	for(const auto &p : a) std::cerr << "\t(" << p.first << ", " << p.second << ")\n";
	std::cerr << "}";
}
template <class T, class U>
void view(const std::map<T, U> &m) {
	std::cerr << "{\n";
	for(const auto &p : m) std::cerr << "\t[" << p.first << "] : " << p.second << "\n";
	std::cerr << "}";
}
template <class T, class U>
void view(const std::pair<T, U> &p) { std::cerr << "(" << p.first << ", " << p.second << ")"; }
template <class T>
void view(const std::set<T> &s) {
	std::cerr << "{ ";
	for(auto &v : s) {
		view(v);
		std::cerr << ", ";
	}
	std::cerr << "\b\b }";
}

template <class T>
void view(const T &e) { std::cerr << e; }
}  // namespace debugger
#ifdef LOCAL
void debug_out() {}
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
	debugger::view(H);
	std::cerr << ", ";
	debug_out(T...);
}
#define debug(...)                                                \
	do {                                                          \
		std::cerr << __LINE__ << " [" << #__VA_ARGS__ << "] : ["; \
		debug_out(__VA_ARGS__);                                   \
		std::cerr << "\b\b]\n";                                   \
	} while(false)
#else
#define debug(...) (void(0))
#endif

// vector macro
template <class T>
int lb(const std::vector<T> &a, const T x) { return std::distance((a).begin(), std::lower_bound((a).begin(), (a).end(), (x))); }
template <class T>
int ub(const std::vector<T> &a, const T x) { return std::distance((a).begin(), std::upper_bound((a).begin(), (a).end(), (x))); }
template <class T>
void UNIQUE(std::vector<T> &a) {
	std::sort(a.begin(), a.end());
	a.erase(std::unique(a.begin(), a.end()), a.end());
}
template <class T>
std::vector<T> press(std::vector<T> &a) {
	auto res = a;
	UNIQUE(res);
	for(auto &v : a)
		v = lb(res, v);
	return res;
}
#define SORTname(a, b, c, ...) c
#define SORT(...) SORTname(__VA_ARGS__, SORT1, SORT0, ...)(__VA_ARGS__)
#define SORT0(a) std::sort((a).begin(), (a).end())
#define SORT1(a, c) std::sort((a).begin(), (a).end(), [](const auto x, const auto y) { return x c y; })
template <class T>
void ADD(std::vector<T> &a, const T x = 1) {
	for(auto &v : a) v += x;
}
template <class T>
void SUB(std::vector<T> &a, const T x = 1) {
	for(auto &v : a) v -= x;
}
std::vector<std::pair<char, int>> rle(const string &s) {
	int n = s.size();
	std::vector<std::pair<char, int>> ret;
	for(int l = 0; l < n;) {
		int r = l + 1;
		for(; r < n and s[l] == s[r]; r++) {}
		ret.emplace_back(s[l], r - l);
		l = r;
	}
	return ret;
}
template <class T>
std::vector<std::pair<T, int>> rle(const std::vector<T> &v) {
	int n = v.size();
	std::vector<std::pair<T, int>> ret;
	for(int l = 0; l < n;) {
		int r = l + 1;
		for(; r < n and v[l] == v[r]; r++) {}
		ret.emplace_back(v[l], r - l);
		l = r;
	}
	return ret;
}
std::vector<int> iota(int n) {
	std::vector<int> p(n);
	std::iota(p.begin(), p.end(), 0);
	return p;
}
template <class T>
struct cum_vector {
public:
	cum_vector() = default;
	template <class U>
	cum_vector(const std::vector<U> &vec) : cum((int)vec.size() + 1) {
		for(int i = 0; i < (int)vec.size(); i++)
			cum[i + 1] = cum[i] + vec[i];
	}
	T prod(int l, int r) {
		return cum[r] - cum[l];
	}

private:
	std::vector<T> cum;
};

// math macro
template <class T, class U>
inline bool chmin(T &a, const U &b) { return a > b ? a = b, true : false; }
template <class T, class U>
inline bool chmax(T &a, const U &b) { return a < b ? a = b, true : false; }
template <class T>
T divup(T x, T y) { return (x + y - 1) / y; }
template <class T>
T POW(T a, long long n) {
	T ret = 1;
	while(n) {
		if(n & 1) ret *= a;
		a *= a;
		n >>= 1;
	}
	return ret;
}
// modpow
long long POW(long long a, long long n, const int mod) {
	long long ret = 1;
	a = (a % mod + mod) % mod;
	while(n) {
		if(n & 1) (ret *= a) %= mod;
		(a *= a) %= mod;
		n >>= 1;
	}
	return ret;
}
template <class T, class F>
T bin_search(T ok, T ng, const F &f) {
	while(abs(ok - ng) > 1) {
		T mid = (ok + ng) >> 1;
		(f(mid) ? ok : ng) = mid;
	}
	return ok;
}
template <class T, class F>
T bin_search(T ok, T ng, const F &f, int loop) {
	for(int i = 0; i < loop; i++) {
		T mid = (ok + ng) / 2;
		(f(mid) ? ok : ng) = mid;
	}
	return ok;
}

// others
struct fast_io {
	fast_io() {
		ios::sync_with_stdio(false);
		cin.tie(nullptr);
		cout << fixed << setprecision(15);
	}
} fast_io_;
const int inf = 1e9;
const ll INF = 1e18;
#pragma endregion

void main_();

int main() {
	int t;
	cin >> t;
	while(t--) main_();
	return 0;
}
#line 7 "f.cpp"

#pragma region datastructure Segment Tree Beats
#line 10 "f.cpp"

template <class T>
struct SegmentTreeBeats {
private:
	size_t n, n_;
	const T MAX = std::numeric_limits<T>::max();
	const T MIN = -MAX;
	std::vector<T> max_v, min_v, smax_v, smin_v, lz_upd, lz_ad, sigm, len;
	std::vector<int> max_c, min_c;

	void init(std::vector<T> &v) {
		n_ = v.size(), n = 1;
		while(n < n_) n *= 2;
		max_v.assign(n * 2 - 1, MIN);
		min_v.assign(n * 2 - 1, MAX);
		smax_v.assign(n * 2 - 1, MIN);
		smin_v.assign(n * 2 - 1, MAX);
		lz_upd.assign(n * 2 - 1, MAX);
		lz_ad.assign(n * 2 - 1, 0);
		len.assign(n * 2 - 1, n);
		sigm.assign(n * 2 - 1, 0);
		max_c.assign(n * 2 - 1, 1);
		min_c.assign(n * 2 - 1, 1);

		for(int i = 0; i < n - 1; i++)
			len[i * 2 + 1] = len[i * 2 + 2] = (len[i] >> 1);

		for(int i = 0; i < n_; i++)
			max_v[i + n - 1] = min_v[i + n - 1] = sigm[i + n - 1] = v[i];

		for(int i = n - 2; i >= 0; i--)
			proc(i);
	}

	void proc(int i) {
		sigm[i] = sigm[i * 2 + 1] + sigm[i * 2 + 2];

		max_v[i] = std::max(max_v[i * 2 + 1], max_v[i * 2 + 2]);

		if(max_v[i * 2 + 1] > max_v[i * 2 + 2]) {
			max_c[i] = max_c[i * 2 + 1];
			smax_v[i] = std::max(smax_v[i * 2 + 1], max_v[i * 2 + 2]);
		}

		if(max_v[i * 2 + 1] < max_v[i * 2 + 2]) {
			max_c[i] = max_c[i * 2 + 2];
			smax_v[i] = std::max(max_v[i * 2 + 1], smax_v[i * 2 + 2]);
		}

		if(max_v[i * 2 + 1] == max_v[i * 2 + 2]) {
			max_c[i] = max_c[i * 2 + 1] + max_c[i * 2 + 2];
			smax_v[i] = std::max(smax_v[i * 2 + 1], smax_v[i * 2 + 2]);
		}

		min_v[i] = std::min(min_v[i * 2 + 1], min_v[i * 2 + 2]);

		if(min_v[i * 2 + 1] < min_v[i * 2 + 2]) {
			min_c[i] = min_c[i * 2 + 1];
			smin_v[i] = std::min(smin_v[i * 2 + 1], min_v[i * 2 + 2]);
		}

		if(min_v[i * 2 + 1] > min_v[i * 2 + 2]) {
			min_c[i] = min_c[i * 2 + 2];
			smin_v[i] = std::min(min_v[i * 2 + 1], smin_v[i * 2 + 2]);
		}

		if(min_v[i * 2 + 1] == min_v[i * 2 + 2]) {
			min_c[i] = min_c[i * 2 + 1] + min_c[i * 2 + 2];
			smin_v[i] = std::min(smin_v[i * 2 + 1], smin_v[i * 2 + 2]);
		}
	}

	void eval(int i) {
		if(lz_upd[i] != MAX) {
			in_update(i * 2 + 1, lz_upd[i]);
			in_update(i * 2 + 2, lz_upd[i]);
			lz_upd[i] = MAX;
			return;
		}

		if(lz_ad[i]) {
			in_add(i * 2 + 1, lz_ad[i]);
			in_add(i * 2 + 2, lz_ad[i]);
			lz_ad[i] = 0;
		}

		if(max_v[i] < max_v[i * 2 + 1]) in_chmin(i * 2 + 1, max_v[i]);
		if(max_v[i] < max_v[i * 2 + 2]) in_chmin(i * 2 + 2, max_v[i]);

		if(min_v[i] > min_v[i * 2 + 1]) in_chmax(i * 2 + 1, min_v[i]);
		if(min_v[i] > min_v[i * 2 + 2]) in_chmax(i * 2 + 2, min_v[i]);
	}

	void in_update(int i, T x) {
		max_v[i] = min_v[i] = x;
		smax_v[i] = MIN, smin_v[i] = MAX;
		max_c[i] = min_c[i] = len[i];
		sigm[i] = len[i] * x;
		lz_upd[i] = x, lz_ad[i] = 0;
	}

	void in_chmin(int i, T x) {
		sigm[i] += (x - max_v[i]) * max_c[i];

		if(max_v[i] == min_v[i])
			max_v[i] = min_v[i] = x;

		else if(max_v[i] == smin_v[i])
			max_v[i] = smin_v[i] = x;

		else
			max_v[i] = x;

		if(lz_upd[i] != MAX and lz_upd[i] > x) lz_upd[i] = x;
	}

	void in_chmax(int i, T x) {
		sigm[i] += (x - min_v[i]) * min_c[i];

		if(min_v[i] == max_v[i])
			min_v[i] = max_v[i] = x;

		else if(min_v[i] == smax_v[i])
			min_v[i] = smax_v[i] = x;

		else
			min_v[i] = x;

		if(lz_upd[i] != MAX and lz_upd[i] < x) lz_upd[i] = x;
	}

	void in_add(int i, T x) {
		max_v[i] += x, min_v[i] += x;

		if(smin_v[i] != MAX) smin_v[i] += x;
		if(smax_v[i] != MIN) smax_v[i] += x;

		sigm[i] += x * len[i];

		if(lz_upd[i] != MAX) lz_upd[i] += x;
		lz_ad[i] += x;
	}

	void chmin(int i, int a, int b, int l, int r, T x) {
		if(b <= l or r <= a or x >= max_v[i]) return;

		if(a <= l and r <= b and smax_v[i] < x) {
			in_chmin(i, x);
			return;
		}

		eval(i);
		chmin(i * 2 + 1, a, b, l, (l + r) >> 1, x);
		chmin(i * 2 + 2, a, b, (l + r) >> 1, r, x);
		proc(i);
	}

	void chmax(int i, int a, int b, int l, int r, T x) {
		if(b <= l or r <= a or x <= min_v[i]) return;

		if(a <= l and r <= b and smin_v[i] > x) {
			in_chmax(i, x);
			return;
		}

		eval(i);
		chmax(i * 2 + 1, a, b, l, (l + r) >> 1, x);
		chmax(i * 2 + 2, a, b, (l + r) >> 1, r, x);
		proc(i);
	}

	void add(int i, int a, int b, int l, int r, T x) {
		if(b <= l or r <= a) return;

		if(a <= l and r <= b) {
			in_add(i, x);
			return;
		}

		eval(i);
		add(i * 2 + 1, a, b, l, (l + r) >> 1, x);
		add(i * 2 + 2, a, b, (l + r) >> 1, r, x);
		proc(i);
	}

	void update(int i, int a, int b, int l, int r, T x) {
		if(b <= l or r <= a) return;

		if(a <= l and r <= b) {
			in_update(i, x);
			return;
		}

		eval(i);
		update(i * 2 + 1, a, b, l, (l + r) >> 1, x);
		update(i * 2 + 2, a, b, (l + r) >> 1, r, x);
		proc(i);
	}

	T sum(int i, int a, int b, int l, int r) {
		if(r <= a || b <= l) return 0;

		if(a <= l && r <= b) return sigm[i];

		eval(i);
		T lv = sum(i * 2 + 1, a, b, l, (l + r) / 2);
		T rv = sum(i * 2 + 2, a, b, (l + r) / 2, r);
		return lv + rv;
	}

	T rangemin(int i, int a, int b, int l, int r) {
		if(r <= a or b <= l) return MAX;

		if(a <= l and r <= b) return min_v[i];

		eval(i);
		T lv = rangemin(i * 2 + 1, a, b, l, (l + r) >> 1);
		T rv = rangemin(i * 2 + 2, a, b, (l + r) >> 1, r);
		return std::min(lv, rv);
	}

	T rangemax(int i, int a, int b, int l, int r) {
		if(r <= a or b <= l) return MIN;

		if(a <= l and r <= b) return max_v[i];

		eval(i);
		T lv = rangemax(i * 2 + 1, a, b, l, (l + r) >> 1);
		T rv = rangemax(i * 2 + 2, a, b, (l + r) >> 1, r);
		return std::max(lv, rv);
	}

	T rangesum(int i, int a, int b, int l, int r) {
		if(r <= a or b <= l) return 0;

		if(a <= l and r <= b) return sigm[i];

		eval(i);
		T lv = rangesum(i * 2 + 1, a, b, l, (l + r) >> 1);
		T rv = rangesum(i * 2 + 2, a, b, (l + r) >> 1, r);
		return lv + rv;
	}

public:
	SegmentTreeBeats() = default;

	SegmentTreeBeats(std::vector<T> &v) {
		init(v);
	}

	SegmentTreeBeats(size_t n, T init_data = 0) {
		std::vector<T> v(n, init_data);
		init(v);
	}

	T operator[](int i) {
		return query_min(i, i + 1);
	}

	void update_chmin(int a, int b, T x) {
		chmin(0, a, b, 0, n, x);
	}

	void update_chmax(int a, int b, T x) {
		chmax(0, a, b, 0, n, x);
	}

	void update_add(int a, int b, T x) {
		add(0, a, b, 0, n, x);
	}

	void update_upd(int a, int b, T x) {
		update(0, a, b, 0, n, x);
	}

	T query_min(int a, int b) {
		return rangemin(0, a, b, 0, n);
	}

	T query_max(int a, int b) {
		return rangemax(0, a, b, 0, n);
	}

	T query_sum(int a, int b) {
		return rangesum(0, a, b, 0, n);
	}
};
#pragma endregion

void main_() {
	int res = 0;
	INT(n);
	VEC(int, p, n);
	//even min > odd max 1
	//even max < odd min
	SUB(p);

	//お気持ち三分探索か？

	//101010
	auto f = [&](int x) {
		vector dp(2, 0);
		dp[1] = -inf;
		REP(i, n) {
			if(p[i] >= x)
				chmax(dp[1], dp[0] + 1);
			else
				chmax(dp[0], dp[1] + 1);
		}
		return max(dp[0], dp[1]);
	};

	{
		int lef = 0, rig = n - 1;
		while(rig - lef >= 3) {
			int c1 = lef + (rig - lef) / 3;
			int c2 = rig - (rig - lef) / 3;
			if(f(c1) >= f(c2))
				rig = c2;
			else
				lef = c1;
		}
		REP(i, lef, rig + 1) {
			chmax(res, f(i));
		}
	}

	auto g = [&](int x) {
		vector dp(2, 0);
		dp[0] = -inf;
		REP(i, n) {
			if(p[i] >= x)
				chmax(dp[1], dp[0] + 1);
			else
				chmax(dp[0], dp[1] + 1);
		}
		return max(dp[0], dp[1]);
	};

	{
		int lef = 0, rig = n - 1;
		while(rig - lef >= 3) {
			int c1 = lef + (rig - lef) / 3;
			int c2 = rig - (rig - lef) / 3;
			if(g(c1) >= g(c2))
				rig = c2;
			else
				lef = c1;
		}
		REP(i, lef, rig + 1) {
			chmax(res, g(i));
		}
	}

	print(res);

	return;
}
0