Submission #772349

#	Time	Username	Problem	Language	Result	Execution time	Memory
772349		marvinthang	Radio Towers (IOI22_towers)	C++17	23 / 100	4038 ms	16924 KiB

towers

/*************************************
*    author: marvinthang             *
*    created: 04.07.2023 09:31:20    *
*************************************/

#include "towers.h"
#include <bits/stdc++.h>

using namespace std;

#define                  fi  first
#define                  se  second
#define                left  ___left
#define               right  ___right
#define                TIME  (1.0 * clock() / CLOCKS_PER_SEC)
#define             MASK(i)  (1LL << (i))
#define           BIT(x, i)  ((x) >> (i) & 1)
#define  __builtin_popcount  __builtin_popcountll
#define              ALL(v)  (v).begin(), (v).end()
#define           REP(i, n)  for (int i = 0, _n = (n); i < _n; ++i)
#define          REPD(i, n)  for (int i = (n); i--; )
#define        FOR(i, a, b)  for (int i = (a), _b = (b); i < _b; ++i) 
#define       FORD(i, b, a)  for (int i = (b), _a = (a); --i >= _a; ) 
#define       FORE(i, a, b)  for (int i = (a), _b = (b); i <= _b; ++i) 
#define      FORDE(i, b, a)  for (int i = (b), _a = (a); i >= _a; --i) 
#define        scan_op(...)  istream & operator >> (istream &in, __VA_ARGS__ &u)
#define       print_op(...)  ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#ifdef LOCAL
		#include "debug.h"
#else
		#define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
		#define DB(...) 23
		#define db(...) 23
		#define debug(...) 23
#endif

template <class U, class V> scan_op(pair <U, V>)  { return in >> u.first >> u.second; }
template <class T> scan_op(vector <T>)  { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> print_op(pair <U, V>)  { return out << '(' << u.first << ", " << u.second << ')'; }
template <size_t i, class T> ostream & print_tuple_utils(ostream &out, const T &tup) { if constexpr(i == tuple_size<T>::value) return out << ")";  else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); }
template <class ...U> print_op(tuple<U...>) { return print_tuple_utils<0, tuple<U...>>(out, u); }
template <class Con, class = decltype(begin(declval<Con>()))> typename enable_if <!is_same<Con, string>::value, ostream&>::type operator << (ostream &out, const Con &con) { out << '{'; for (__typeof(con.begin()) it = con.begin(); it != con.end(); ++it) out << (it == con.begin() ? "" : ", ") << *it; return out << '}'; }

const int INF = 1e9;

struct Node {
	int ma, s_p, p_s;
	pair <int, int> mi;
	Node(): ma(-INF), mi(INF, INF), s_p(-INF), p_s(-INF) {}
	Node(int h, int i): ma(h), mi(h, i), s_p(-INF), p_s(-INF) {}
	Node operator + (const Node &other) {
		Node res;
		res.ma = max(ma, other.ma);
		res.mi = min(mi, other.mi);
		res.s_p = max({s_p, other.s_p, other.ma - mi.fi});
		res.p_s = max({p_s, other.p_s, ma - other.mi.fi});
		return res;
	}
};

// end of template

int N;
vector <int> H;
vector <Node> st;

void build(int i, int l, int r) {
	if (r - l == 1) {
		st[i] = Node(H[l], l);
		return;
	}
	int m = l + r >> 1;
	build(i << 1, l, m);
	build(i << 1 | 1, m, r);
	st[i] = st[i << 1] + st[i << 1 | 1];
}

Node get(int i, int l, int r, int u, int v) {
	if (l >= v || r <= u || u >= v) return Node();
	if (u <= l && r <= v) return st[i];
	int m = l + r >> 1;
	return get(i << 1, l, m, u, v) + get(i << 1 | 1, m, r, u, v);
}

void init(int n, vector<int> h) {
	N = n;
	H = h;
	st.resize(N * 4 + 23);
	build(1, 0, N);
}

int max_towers(int l, int r, int d) {
	vector <int> left(N), right(N);
	vector <pair <int, int>> events;
	REP(i, N) {
		events.emplace_back(H[i], i);
		events.emplace_back(H[i] + d, -1 - i);
	}
	sort(events.rbegin(), events.rend());
	set <int> s;
	for (auto [h, x]: events) {
		if (x >= 0) s.insert(x);
		else {
			x = -1 - x;
			auto it = s.lower_bound(x);
			left[x] = it != s.begin() ? *prev(it) : -1;
			right[x] = it != s.end() ? *it : N;
		}
	}
	s.clear();
	reverse(ALL(events));
	for (auto [h, x]: events) if (x >= 0) {
		auto it = s.lower_bound(x);
		if (it != s.end() && *it < right[x]) continue;
		if (it != s.begin() && *prev(it) > left[x]) continue;
		s.insert(x);
	}
	while (!s.empty() && *s.begin() < l) s.erase(s.begin());
	while (!s.empty() && *s.rbegin() > r) s.erase(*s.rbegin());
	int res = s.size();
	if (!res) {
		s.insert(get(1, 0, N, l, r + 1).mi.se);
		++res;
	}
	int x = *s.begin();
	int y = *s.rbegin();
	res += get(1, 0, N, l, x).s_p >= d;
	res += get(1, 0, N, y + 1, r + 1).p_s >= d;
	return res;
}

Compilation message (stderr)

towers.cpp: In constructor 'Node::Node()':
towers.cpp:48:18: warning: 'Node::mi' will be initialized after [-Wreorder]
   48 |  pair <int, int> mi;
      |                  ^~
towers.cpp:47:10: warning:   'int Node::s_p' [-Wreorder]
   47 |  int ma, s_p, p_s;
      |          ^~~
towers.cpp:49:2: warning:   when initialized here [-Wreorder]
   49 |  Node(): ma(-INF), mi(INF, INF), s_p(-INF), p_s(-INF) {}
      |  ^~~~
towers.cpp: In constructor 'Node::Node(int, int)':
towers.cpp:48:18: warning: 'Node::mi' will be initialized after [-Wreorder]
   48 |  pair <int, int> mi;
      |                  ^~
towers.cpp:47:10: warning:   'int Node::s_p' [-Wreorder]
   47 |  int ma, s_p, p_s;
      |          ^~~
towers.cpp:50:2: warning:   when initialized here [-Wreorder]
   50 |  Node(int h, int i): ma(h), mi(h, i), s_p(-INF), p_s(-INF) {}
      |  ^~~~
towers.cpp: In function 'void build(int, int, int)':
towers.cpp:72:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   72 |  int m = l + r >> 1;
      |          ~~^~~
towers.cpp: In function 'Node get(int, int, int, int, int)':
towers.cpp:81:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   81 |  int m = l + r >> 1;
      |          ~~^~~

• Subtask 1: 0 / 4
• Subtask 2: 11 / 11
• Subtask 3: 12 / 12
• Subtask 4: 0 / 14
• Subtask 5: 0 / 17
• Subtask 6: 0 / 19
• Subtask 7: 0 / 23