Submission #1253151

#	Time	Username	Problem	Language	Result	Execution time	Memory
1253151		Benq	Migrations (IOI25_migrations)	C++20	100 / 100	32 ms	1296 KiB

migrations

#include "migrations.h"

#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
#define sz(x) int(size(x))
#define bg(x) begin(x)
#define all(x) bg(x), end(x)
#define rall(x) rbegin(x), rend(x)
#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(const V<T> &a, const T &b) { return int(lb(all(a), b) - bg(a)); }
tcT > int upb(const 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 = 998244353;  // 1e9+7;
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 <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, bool print_nd> struct Writer {
	string comma() const { return debug ? "," : ""; }
	template <class T> constexpr char Space(const T &) const {
		return print_nd && (Iterable<T>::value or IsTuple<T>::value) ? '\n'
		                                                             : ' ';
	}
	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, true>{}.print(ts...);
}
template <class... Ts> void ps(Ts const &...ts) {
	Writer<cout, false, true>{}.print_with_sep(" ", ts...);
}
}  // namespace IO

inline namespace Debug {
template <typename... Args> void err(Args... args) {
	Writer<cerr, true, false>{}.print_with_sep(" | ", args...);
}
template <typename... Args> void errn(Args... args) {
	Writer<cerr, true, 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)
#define dbgn(args...) err_prefix(__FUNCTION__, __LINE__, #args), errn(args)
#else
#define dbg(...)
#define dbgn(args...)
#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

const int D = 14;
V<AR<int, 14>> p;
vi depth;
AR<int, 2> diameter;
AR<vi, 2> cands;

int lca(int a, int b) {
	if (depth.at(a) < depth.at(b)) swap(a, b);
	R0F(d, D) if ((depth.at(a) - depth.at(b)) & (1 << d)) a = p.at(a).at(d);
	if (a == b) return a;
	R0F(d, D) if (p.at(a).at(d) != p.at(b).at(d)) {
		a = p.at(a).at(d);
		b = p.at(b).at(d);
	}
	return p.at(a).at(0);
}

int dist(int a, int b) {
	return depth.at(a) + depth.at(b) - 2 * depth.at(lca(a, b));
}

int getpot(pi p, int cons = 1) { return (p.f + cons) * (p.s + cons); }

template <class T> V<T> extract(V<T> v, int parts, int ret) {
	assert(sz(v));
	while (sz(v) % parts) v.pb(v.bk);
	assert(0 <= ret && ret < parts);
	return V<T>(begin(v) + sz(v) / parts * ret,
	            begin(v) + sz(v) / parts * (ret + 1));
}

int idx(vi &v, int goal, int parts) {
	dbg("IDX", sz(v), v.ft, goal, parts);
	assert(sz(v));
	while (sz(v) % parts) v.pb(v.bk);
	int i = 0;
	while (v.at(i) != goal) {
		++i;
		assert(i < sz(v));
	}

	int ret = i * parts / sz(v);
	v = extract(v, parts, ret);
	dbg("RET", ret);
	return ret;
}

// 10000, 182 (1 move)
// 553, 25 (1 move)
// 81, 6 (1 move)
// 23, rest (6 moves)

vi cuts;

void init_cuts(int N) {
	cuts = {N};              // cuts[6]
	cuts.pb(cuts.bk - 3);    // cuts[5]
	cuts.pb(cuts.bk - 2);    // cuts[4]
	cuts.pb(cuts.bk - 2);    // cuts[3]
	cuts.pb(cuts.bk - 6);    // cuts[2]
	cuts.pb(cuts.bk - 20);   // cuts[1]
	cuts.pb(cuts.bk - 140);  // cuts[0]
	reverse(all(cuts));
	assert(sz(cuts) == 7);
}

pi pos_val;

// full credit
vi with_label;
const V<V<AR<int, 2>>> partitions{{{0, 4}, {0, 5}, {0, 6}, {0, 8}, {8, 4}},
                                  {{0, 7}, {1, 7}, {1, 4}, {1, 8}, {8, 7}},
                                  {{1, 5}, {1, 6}, {2, 6}, {2, 8}, {8, 6}},
                                  {{2, 4}, {2, 5}, {3, 5}, {3, 8}, {8, 5}},
                                  {{3, 4}, {3, 6}, {3, 7}, {2, 7}}};
V<AR<int, 2>> cand_pairs;

bool common(AR<int, 2> a, AR<int, 2> b) {
	each(x, a) each(y, b) if (x == y) return true;
	return false;
}

V<AR<int, 2>> add_all(V<AR<int, 2>> v, int nvert) {
	V<AR<int, 2>> cands = v;
	each(t, v) {
		cands.pb({t[0], nvert});
		cands.pb({t[1], nvert});
	}
	remDup(cands);
	return cands;
}

V<AR<int, 2>> valid_ordering(V<AR<int, 2>> v) {
	sor(v);
	do {
		bool ok = true;
		for (int i = 0; i + 1 < sz(v); i += 2) {
			if (!common(v[i], v[i + 1])) {
				ok = false;
				break;
			}
		}
		if (ok) return v;
	} while (next_permutation(all(v)));
	assert(false);
}

AR<int, 2> pair_to_edge(AR<int, 2> t) {
	return {with_label.at(t[0]), with_label.at(t[1])};
}

bool edge_eq(AR<int, 2> a, AR<int, 2> b) {
	if (a == b) return true;
	if (a == AR<int, 2>{b[1], b[0]}) return true;
	return false;
}

int c2(int x) { return x * (x + 1) / 2; };

int send_message(int N, int i, int Pi) {
	if (i == 1) {
		p.eb(), depth.eb();
		F0R(j, 2) cands.at(j).pb(0);
		init_cuts(N);
	}

	p.eb();
	p.bk.at(0) = Pi;
	depth.pb(depth.at(Pi) + 1);
	FOR(d, 1, D) p.bk.at(d) = p.at(p.bk.at(d - 1)).at(d - 1);
	assert(sz(p) == i + 1);

	F0R(j, 2) {
		if (dist(i, diameter.at(j)) > dist(diameter.at(0), diameter.at(1))) {
			diameter.at(j ^ 1) = i;
			break;
		}
	}

	int cut_idx = 0;
	while (cuts.at(cut_idx + 1) <= i) ++cut_idx;
	if (cut_idx > 0 && cuts.at(cut_idx) == i) {
		FOR(j, cuts.at(cut_idx - 1) + 1, cuts.at(cut_idx)) {
			cands.at(0).pb(j);
			cands.at(1).pb(j);
		}
	}

	int msg = 0;
	if (i >= cuts.at(5)) {
		if (i == cuts.at(5)) {
			dbg("e phase 2", i, sz(cands.at(0)));
			assert(sz(cands.at(0)) == 4 && sz(cands.at(1)) == 4);
			with_label = {};
			with_label.ins(end(with_label), all(cands.at(0)));
			with_label.ins(end(with_label), all(cands.at(1)));
			with_label.pb(i);

			while (true) {
				bool found = 0;
				each(t, partitions.at(msg)) {
					if (diameter == pair_to_edge(t)) { found = true; }
				}
				if (found) break;
				++msg;
			}

			cand_pairs = partitions.at(msg);
		} else if (i == cuts.at(5) + 1) {
			dbg("e phase 3", cand_pairs);
			with_label.pb(i);
			cand_pairs = add_all(cand_pairs, 9);
			cand_pairs = valid_ordering(cand_pairs);
			while (sz(cand_pairs) < 10) cand_pairs.pb(cand_pairs.bk);
			assert(sz(cand_pairs) == 10);
			int ret = 0;
			while (!edge_eq(diameter, pair_to_edge(cand_pairs.at(ret)))) {
				++ret;
			}
			msg = ret / 2;
			cand_pairs = extract(cand_pairs, 5, msg);
		} else {
			dbg("e phase 4", cand_pairs);
			with_label.pb(i);
			assert(i == cuts.at(5) + 2);
			cand_pairs = add_all(cand_pairs, 10);
			assert(sz(cand_pairs) <= 5);
			while (!edge_eq(diameter, pair_to_edge(cand_pairs.at(msg)))) ++msg;
			dbg(diameter);
		}
	} else if (i >= cuts.at(0)) {
		if (i == cuts.at(cut_idx)) {
			cands.at(0).pb(i);
			cands.at(1).pb(i);
			dbg("phase 1", i, sz(cands.at(0)), sz(cands.at(1)));
			assert(sz(cands.at(0)) == sz(cands.at(1)));
			const int space = cuts.at(cut_idx + 1) - cuts.at(cut_idx);
			const int num_cands = 4 * space + 1;
			int to_encrypt = 0;
			if (cut_idx == 0) {
				int sqrt_cands = 1;
				while (c2(sqrt_cands + 1) <= num_cands) ++sqrt_cands;
				if (diameter.at(0) < diameter.at(1))
					swap(diameter.at(0), diameter.at(1));
				to_encrypt = c2(idx(cands.at(0), diameter.at(0), sqrt_cands)) +
				             idx(cands.at(1), diameter.at(1), sqrt_cands);
			} else {
				int sqrt_cands = sqrt(num_cands);
				F0R(j, 2) {
					to_encrypt = sqrt_cands * to_encrypt +
					             idx(cands.at(j), diameter.at(j), sqrt_cands);
				}
			}
			assert(0 <= to_encrypt && to_encrypt < num_cands);
			dbg(i, to_encrypt);
			if (to_encrypt == 4 * space) {
				pos_val = {-1, -1};
			} else {
				pos_val = {i + to_encrypt / 4, 1 + to_encrypt % 4};
			}
		}
		if (i == pos_val.f) {
			assert(1 <= pos_val.s && pos_val.s <= 4);
			msg = pos_val.s;
		}
	} else {
		F0R(j, 2) cands.at(j).pb(i);
	}
	return msg;
}

pi arr_to_pair(AR<int, 2> a) { return {a[0], a[1]}; }

std::pair<int, int> longest_path(std::vector<int> S) {
	p = {};
	depth = {};
	diameter = {};
	cands = {};

	int N = sz(S);
	init_cuts(N);

	F0R(i, N) {
		// dbg("AT", i);
		int cut_idx = 0;
		while (cuts.at(cut_idx + 1) <= i) ++cut_idx;

		if (cut_idx > 0 && cuts.at(cut_idx) == i) {
			int space = cuts.at(cut_idx) - cuts.at(cut_idx - 1);
			int num_cands = 4 * space + 1;
			int sqrt_cands = 0;
			if (cut_idx == 1) {
				while (c2(sqrt_cands + 1) <= num_cands) ++sqrt_cands;
			} else {
				sqrt_cands = sqrt(num_cands);
			}
			int to_encrypt = 0;

			if (pos_val == mp(-1, -1)) to_encrypt = 4 * space;
			else {
				to_encrypt =
				    (pos_val.f - cuts.at(cut_idx - 1)) * 4 + (pos_val.s - 1);
			}

			assert(0 <= to_encrypt && to_encrypt < num_cands);

			AR<int, 2> idx{};
			if (cut_idx == 1) {
				while (c2(idx.at(0) + 1) <= to_encrypt) ++idx.at(0);
				idx.at(1) = to_encrypt - c2(idx.at(0));
			} else {
				idx = {to_encrypt / sqrt_cands, to_encrypt % sqrt_cands};
			}

			dbg("rextract", cuts.at(cut_idx - 1), pos_val, to_encrypt, cut_idx,
			    sqrt_cands, idx);

			F0R(j, 2)
			cands.at(j) = extract(cands.at(j), sqrt_cands, idx.at(j));

			FOR(j, cuts.at(cut_idx - 1) + 1, cuts.at(cut_idx)) {
				cands.at(0).pb(j);
				cands.at(1).pb(j);
			}
			dbg("DONE");
		}

		int msg = S.at(i);
		if (i >= cuts.at(5)) {
			if (i == cuts.at(5)) {
				dbg("d phase 2", i, sz(cands.at(0)));
				dbg(cands.at(0), cands.at(1));

				assert(sz(cands.at(0)) == 4 && sz(cands.at(1)) == 4);
				with_label = {};
				with_label.ins(end(with_label), all(cands.at(0)));
				with_label.ins(end(with_label), all(cands.at(1)));
				with_label.pb(i);

				cand_pairs = partitions.at(msg);
			} else if (i == cuts.at(5) + 1) {
				dbg("d phase 3", i, cand_pairs);
				with_label.pb(i);
				cand_pairs = add_all(cand_pairs, 9);
				cand_pairs = valid_ordering(cand_pairs);
				while (sz(cand_pairs) < 10) cand_pairs.pb(cand_pairs.bk);
				assert(sz(cand_pairs) == 10);
				cand_pairs = extract(cand_pairs, 5, msg);
			} else {
				dbg("d phase 4", i, cand_pairs);
				assert(i == cuts.at(5) + 2);
				with_label.pb(i);
				assert(i == cuts.at(5) + 2);
				cand_pairs = add_all(cand_pairs, 10);
				assert(sz(cand_pairs) <= 5);
				return arr_to_pair(pair_to_edge(cand_pairs.at(msg)));
			}
		} else if (i >= cuts.at(0)) {
			if (i == cuts.at(cut_idx)) {
				pos_val = {-1, -1};
				cands.at(0).pb(i);
				cands.at(1).pb(i);
			}
			if (msg != 0) {
				assert(pos_val == mp(-1, -1));
				pos_val = {i, msg};
			}
		} else {
			assert(msg == 0);
			F0R(j, 2) cands.at(j).pb(i);
		}
		if (i == N - 1) {
			F0R(j, 2) assert(sz(cands.at(j)) == 1);
			return {cands.at(0).ft, cands.at(1).ft};
		}
	}
	assert(false);
}

Compilation message (stderr)

migrations.cpp: In function 'void FileIO::setIn(str)':
migrations.cpp:248:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  248 | void setIn(str s) { freopen(s.c_str(), "r", stdin); }
      |                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
migrations.cpp: In function 'void FileIO::setOut(str)':
migrations.cpp:249:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  249 | void setOut(str s) { freopen(s.c_str(), "w", stdout); }
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 30 / 30
• Subtask 2: 70 / 70