Submission #842472

#	Time	Username	Problem	Language	Result	Execution time	Memory
842472		Benq	Soccer Stadium (IOI23_soccer)	C++17	100 / 100	1860 ms	477344 KiB

soccer

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <climits>
#include <cmath>
#include <complex>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <vector>
using namespace std;

using ll = long long;
using db = long double;  // or double, if TL is tight
using str = string;      // yay python!

// pairs
using pi = pair<int, int>;
using pl = pair<ll, ll>;
using pd = pair<db, db>;
#define mp make_pair
#define f first
#define s second

#define tcT template <class T
#define tcTU tcT, class U
// ^ lol this makes everything look weird but I'll try it
tcT > using V = vector<T>;
tcT, size_t SZ > using AR = array<T, SZ>;
using vi = V<int>;
using vb = V<bool>;
using vl = V<ll>;
using vd = V<db>;
using vs = V<str>;
using vpi = V<pi>;
using vpl = V<pl>;
using vpd = V<pd>;

// vectors
// oops size(x), rbegin(x), rend(x) need C++17
#define sz(x) int((x).size())
#define bg(x) begin(x)
#define all(x) bg(x), end(x)
#define rall(x) x.rbegin(), x.rend()
#define sor(x) sort(all(x))
#define rsz resize
#define ins insert
#define pb push_back
#define eb emplace_back
#define ft front()
#define bk back()

#define lb lower_bound
#define ub upper_bound
tcT > int lwb(V<T> &a, const T &b) { return int(lb(all(a), b) - bg(a)); }
tcT > int upb(V<T> &a, const T &b) { return int(ub(all(a), b) - bg(a)); }

// loops
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define F0R(i, a) FOR(i, 0, a)
#define ROF(i, a, b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i, a) ROF(i, 0, a)
#define rep(a) F0R(_, a)
#define each(a, x) for (auto &a : x)

const int MOD = (int)1e9 + 7;  // 998244353;
const int MX = (int)2e5 + 5;
const ll BIG = 1e18;  // not too close to LLONG_MAX
const db PI = acos((db)-1);
const int dx[4]{1, 0, -1, 0}, dy[4]{0, 1, 0, -1};  // for every grid problem!!
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());
template <class T> using pqg = priority_queue<T, vector<T>, greater<T>>;

// bitwise ops
// also see https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html
constexpr int pct(int x) { return __builtin_popcount(x); }  // # of bits set
constexpr int bits(int x) {  // assert(x >= 0); // make C++11 compatible until
	                         // USACO updates ...
	return x == 0 ? 0 : 31 - __builtin_clz(x);
}  // floor(log2(x))
constexpr int p2(int x) { return 1 << x; }
constexpr int msk2(int x) { return p2(x) - 1; }

ll cdiv(ll a, ll b) {
	return a / b + ((a ^ b) > 0 && a % b);
}  // divide a by b rounded up
ll fdiv(ll a, ll b) {
	return a / b - ((a ^ b) < 0 && a % b);
}  // divide a by b rounded down

tcT > bool ckmin(T &a, const T &b) {
	return b < a ? a = b, 1 : 0;
}  // set a = min(a,b)
tcT > bool ckmax(T &a, const T &b) {
	return a < b ? a = b, 1 : 0;
}  // set a = max(a,b)

tcTU > T fstTrue(T lo, T hi, U f) {
	++hi;
	assert(lo <= hi);  // assuming f is increasing
	while (lo < hi) {  // find first index such that f is true
		T mid = lo + (hi - lo) / 2;
		f(mid) ? hi = mid : lo = mid + 1;
	}
	return lo;
}
tcTU > T lstTrue(T lo, T hi, U f) {
	--lo;
	assert(lo <= hi);  // assuming f is decreasing
	while (lo < hi) {  // find first index such that f is true
		T mid = lo + (hi - lo + 1) / 2;
		f(mid) ? lo = mid : hi = mid - 1;
	}
	return lo;
}
tcT > void remDup(vector<T> &v) {  // sort and remove duplicates
	sort(all(v));
	v.erase(unique(all(v)), end(v));
}
tcTU > void safeErase(T &t, const U &u) {
	auto it = t.find(u);
	assert(it != end(t));
	t.erase(it);
}

inline namespace IO {
#define SFINAE(x, ...)                                                         \
	template <class, class = void> struct x : std::false_type {};              \
	template <class T> struct x<T, std::void_t<__VA_ARGS__>> : std::true_type {}

SFINAE(DefaultI, decltype(std::cin >> std::declval<T &>()));
SFINAE(DefaultO, decltype(std::cout << std::declval<T &>()));
SFINAE(IsTuple, typename std::tuple_size<T>::type);
SFINAE(Iterable, decltype(std::begin(std::declval<T>())));

template <class T> constexpr char Space(const T &) {
	return (Iterable<T>::value or IsTuple<T>::value) ? '\n' : ' ';
}

template <auto &is> struct Reader {
	template <class T> void Impl(T &t) {
		if constexpr (DefaultI<T>::value) is >> t;
		else if constexpr (Iterable<T>::value) {
			for (auto &x : t) Impl(x);
		} else if constexpr (IsTuple<T>::value) {
			std::apply([this](auto &...args) { (Impl(args), ...); }, t);
		} else static_assert(IsTuple<T>::value, "No matching type for read");
	}
	template <class... Ts> void read(Ts &...ts) { ((Impl(ts)), ...); }
};

template <class... Ts> void re(Ts &...ts) { Reader<cin>{}.read(ts...); }
#define def(t, args...)                                                        \
	t args;                                                                    \
	re(args);

template <auto &os, bool debug> struct Writer {
	string comma() const { return debug ? "," : ""; }
	template <class T> void Impl(T const &t) const {
		if constexpr (DefaultO<T>::value) os << t;
		else if constexpr (Iterable<T>::value) {
			if (debug) os << '{';
			int i = 0;
			for (auto &&x : t)
				((i++) ? (os << comma() << Space(x), Impl(x)) : Impl(x));
			if (debug) os << '}';
		} else if constexpr (IsTuple<T>::value) {
			if (debug) os << '(';
			std::apply(
			    [this](auto const &...args) {
				    int i = 0;
				    (((i++) ? (os << comma() << " ", Impl(args)) : Impl(args)),
				     ...);
			    },
			    t);
			if (debug) os << ')';
		} else static_assert(IsTuple<T>::value, "No matching type for print");
	}
	template <class T> void ImplWrapper(T const &t) const {
		if (debug) os << "\033[0;31m";
		Impl(t);
		if (debug) os << "\033[0m";
	}
	template <class... Ts> void print(Ts const &...ts) const {
		((Impl(ts)), ...);
	}
	template <class F, class... Ts>
	void print_with_sep(const std::string &sep, F const &f,
	                    Ts const &...ts) const {
		ImplWrapper(f), ((os << sep, ImplWrapper(ts)), ...), os << '\n';
	}
	void print_with_sep(const std::string &) const { os << '\n'; }
};

template <class... Ts> void pr(Ts const &...ts) {
	Writer<cout, false>{}.print(ts...);
}
template <class... Ts> void ps(Ts const &...ts) {
	Writer<cout, false>{}.print_with_sep(" ", ts...);
}
}  // namespace IO

inline namespace Debug {
template <typename... Args> void err(Args... args) {
	Writer<cerr, true>{}.print_with_sep(" | ", args...);
}

void err_prefix(str func, int line, string args) {
	cerr << "\033[0;31m\u001b[1mDEBUG\033[0m"
	     << " | "
	     << "\u001b[34m" << func << "\033[0m"
	     << ":"
	     << "\u001b[34m" << line << "\033[0m"
	     << " - "
	     << "[" << args << "] = ";
}

#ifdef LOCAL
#define dbg(args...) err_prefix(__FUNCTION__, __LINE__, #args), err(args)
#else
#define dbg(...)
#endif

const auto beg_time = std::chrono::high_resolution_clock::now();
// https://stackoverflow.com/questions/47980498/accurate-c-c-clock-on-a-multi-core-processor-with-auto-overclock?noredirect=1&lq=1
double time_elapsed() {
	return chrono::duration<double>(std::chrono::high_resolution_clock::now() -
	                                beg_time)
	    .count();
}
}  // namespace Debug

inline namespace FileIO {
void setIn(str s) { freopen(s.c_str(), "r", stdin); }
void setOut(str s) { freopen(s.c_str(), "w", stdout); }
void setIO(str s = "") {
	cin.tie(0)->sync_with_stdio(0);  // unsync C / C++ I/O streams
	cout << fixed << setprecision(12);
	// cin.exceptions(cin.failbit);
	// throws exception when do smth illegal
	// ex. try to read letter into int
	if (sz(s)) setIn(s + ".in"), setOut(s + ".out");  // for old USACO
}
}  // namespace FileIO

#include "soccer.h"

/**
 * Description: 1D range minimum query. If TL is an issue, use
 * arrays instead of vectors and store values instead of indices.
 * Source: KACTL
 * Verification:
 * https://cses.fi/problemset/stats/1647/
 * http://wcipeg.com/problem/ioi1223
 * https://pastebin.com/ChpniVZL
 * Memory: O(N\log N)
 * Time: O(1)
 */

tcT > struct RMQ {  // floor(log_2(x))
	int level(int x) { return 31 - __builtin_clz(x); }
	V<T> v;
	V<vi> jmp;
	int cmb(int a, int b) {
		return v[a] == v[b] ? min(a, b) : (v[a] < v[b] ? a : b);
	}
	void init(const V<T> &_v) {
		v = _v;
		jmp = {vi(sz(v))};
		iota(all(jmp[0]), 0);
		for (int j = 1; 1 << j <= sz(v); ++j) {
			jmp.pb(vi(sz(v) - (1 << j) + 1));
			F0R(i, sz(jmp[j]))
			jmp[j][i] = cmb(jmp[j - 1][i], jmp[j - 1][i + (1 << (j - 1))]);
		}
	}
	int index(int l, int r) {
		assert(l <= r);
		int d = level(r - l + 1);
		return cmb(jmp[d][l], jmp[d][r - (1 << d) + 1]);
	}
	T query(int l, int r) { return v[index(l, r)]; }
};

tcT > struct RMaxQ {  // floor(log_2(x))
	int level(int x) { return 31 - __builtin_clz(x); }
	V<T> v;
	V<vi> jmp;
	int cmb(int a, int b) {
		return v[a] == v[b] ? min(a, b) : (v[a] > v[b] ? a : b);
	}
	void init(const V<T> &_v) {
		v = _v;
		jmp = {vi(sz(v))};
		iota(all(jmp[0]), 0);
		for (int j = 1; 1 << j <= sz(v); ++j) {
			jmp.pb(vi(sz(v) - (1 << j) + 1));
			F0R(i, sz(jmp[j]))
			jmp[j][i] = cmb(jmp[j - 1][i], jmp[j - 1][i + (1 << (j - 1))]);
		}
	}
	int index(int l, int r) {
		assert(l <= r);
		int d = level(r - l + 1);
		return cmb(jmp[d][l], jmp[d][r - (1 << d) + 1]);
	}
	T query(int l, int r) { return v[index(l, r)]; }
};

int biggest_stadium(int N, std::vector<std::vector<int>> F) {
	V<vi> row(N, vi(N, -1)), col(N, vi(N, -1));
	F0R(r, N) {
		F0R(c, N) {
			if (F[r][c]) {
				row[r][c] = c;
				col[r][c] = r;
			} else {
				if (c) row[r][c] = row[r][c - 1];
				if (r) col[r][c] = col[r - 1][c];
			}
		}
	}
	auto empty = [&](int r, int c1, int c2) { return row.at(r).at(c2) < c1; };
	V<pair<pi, pi>> rects;
	auto cand_rect = [&](pi x, pi y) {
		if (x.s == N - 1 || row.at(x.s + 1).at(y.s) >= y.f) {
			rects.pb({x, y});
		}
	};
	F0R(r, N) {
		vpi stk{{r, -1}};
		F0R(c, N) {
			// dbg(r, c, col[r][c]);
			while (sz(stk) && stk.bk.f <= col[r][c]) {
				auto p = stk.bk;
				stk.pop_back();
				if (sz(stk) && p.f < col[r][c]) {
					// dbg("HA", p, col[r][c]);
					cand_rect({p.f + 1, r}, {stk.bk.s + 1, c - 1});
				}
			}
			stk.pb({col[r][c], c});
		}
		while (sz(stk)) {
			auto p = stk.bk;
			stk.pop_back();
			if (sz(stk)) {
				// dbg("HA", p, col[r][c]);
				cand_rect({p.f + 1, r}, {stk.bk.s + 1, N - 1});
			}
		}
	}
	auto height = [&](const auto &a) { return a.f.s - a.f.f + 1; };
	auto width = [&](const auto &a) { return a.s.s - a.s.f + 1; };
	sort(all(rects), [](const auto &a, const auto &b) {
		return a.s.s - a.s.f + 1 < b.s.s - b.s.f + 1;
	});

	V<pair<pair<pi, pi>, int>> order;
	F0R(i, sz(rects)) { order.pb({rects[i], i}); }

	auto locate = [&](pair<pi, pi> p) {
		// dbg("LOCATE", p);
		int i = lwb(order, {p, 0});
		assert(order.at(i).f == p);
		// dbg("DONE LOCATE");
		return order.at(i).s;
	};
	sor(order);
	auto contains = [&](pi a, pi b) {
		return a.f <= b.f && b.s <= a.s && a != b;
	};
	V<RMaxQ<int>> r_max_q(N);
	V<RMQ<int>> r_min_q(N);
	F0R(r, N) { r_max_q[r].init(col[r]); }
	{
		V<vi> ncol(N + 1, vi(N, N));
		R0F(r, N) {
			F0R(c, N) {
				if (F[r][c]) ncol[r][c] = r;
				else ncol[r][c] = ncol[r + 1][c];
			}
			r_min_q[r].init(ncol[r]);
		}
	}
	vi dp(sz(rects));
	int ans = 0;
	F0R(i, sz(rects)) {
		int r1 = rects[i].f.f;
		int r2 = rects[i].f.s;
		int c1 = rects[i].s.f;
		int c2 = rects[i].s.s;

		auto cand_rect = [&](int c_lo, int c_hi) {
			assert(c_lo <= c_hi);
			int r_lo = r_max_q.at(r1).query(c_lo, c_hi) + 1;
			int r_hi = r_min_q.at(r2).query(c_lo, c_hi) - 1;
			int j = locate({{r_lo, r_hi}, {c_lo, c_hi}});
			ckmax(dp[i], dp[j] + (height(rects[j]) - height(rects[i])) *
			                         width(rects[j]));
		};

		// dbg("BEGIN");
		for (int r : {r1 - 1, r2 + 1}) {
			int c = c2 + 1;
			while (c > c1) {
				// dbg(r, c);
				int prev_c =
				    ((r < 0 || r >= N) ? c - 1
				                       : max(row.at(r).at(c - 1), c1 - 1));
				if (prev_c + 1 < c) { cand_rect(prev_c + 1, c - 1); }
				c = prev_c;
			}
			// dbg("HI");
		}
		// dbg("END");
		ckmax(ans, dp[i] + height(rects[i]) * width(rects[i]));
	}
	return ans;
}

Compilation message (stderr)

soccer.cpp: In function 'int biggest_stadium(int, std::vector<std::vector<int, std::allocator<int> > >)':
soccer.cpp:331:7: warning: variable 'empty' set but not used [-Wunused-but-set-variable]
  331 |  auto empty = [&](int r, int c1, int c2) { return row.at(r).at(c2) < c1; };
      |       ^~~~~
soccer.cpp:378:7: warning: variable 'contains' set but not used [-Wunused-but-set-variable]
  378 |  auto contains = [&](pi a, pi b) {
      |       ^~~~~~~~
soccer.cpp: In function 'void FileIO::setIn(str)':
soccer.cpp:242:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  242 | void setIn(str s) { freopen(s.c_str(), "r", stdin); }
      |                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
soccer.cpp: In function 'void FileIO::setOut(str)':
soccer.cpp:243:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  243 | void setOut(str s) { freopen(s.c_str(), "w", stdout); }
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 6 / 6
• Subtask 2: 8 / 8
• Subtask 3: 22 / 22
• Subtask 4: 18 / 18
• Subtask 5: 16 / 16
• Subtask 6: 30 / 30