Submission #767972

#	Time	Username	Problem	Language	Result	Execution time	Memory
767972		marvinthang	Meetings (IOI18_meetings)	C++17	100 / 100	2146 ms	434776 KiB

meetings

/*************************************
*    author: marvinthang             *
*    created: 27.06.2023 11:42:33    *
*************************************/

#include "meetings.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 << '}'; }
template <class A, class B> bool minimize(A &a, B b)  { if (a > b) { a = b; return true; } return false; }
template <class A, class B> bool maximize(A &a, B b)  { if (a < b) { a = b; return true; } return false; }

// end of template

const long long INF = 1e18;

struct Line {
	long long a, b;
	int len;
	Line(long long a = 0, long long b = 0, int len = 0): a(a), b(b), len(len) {}
	long long eval(int x) {
		return a * x + b;
	}
	friend print_op(Line) {
		return out << make_pair(u.a, u.b);
	}
};

vector <long long> minimum_costs(std::vector<int> H, vector <int> L, vector <int> R) {
	int N = H.size();
	int Q = L.size();

	stack <int> st;
	vector <int> par(N, -1);
	REP(i, N) {
		while (!st.empty() && H[st.top()] <= H[i]) st.pop();
		if (!st.empty()) par[i] = st.top();
		st.push(i);
	}
	while (!st.empty()) st.pop();
	REPD(i, N) {
		while (!st.empty() && H[st.top()] < H[i]) st.pop();
		if (!st.empty() && (par[i] == -1 || H[par[i]] > H[st.top()])) par[i] = st.top();
		st.push(i);
	}

	int root = find(ALL(par), -1) - par.begin();

	vector <vector <pair <int, int>>> max_val;
	max_val.push_back(vector<pair <int, int>>(N));
	REP(i, N) max_val[0][i] = make_pair(H[i], i);
	for (int k = 1; MASK(k) <= N; ++k) {
		vector <pair <int, int>> nxt;
		REP(i, N - MASK(k) + 1) nxt.push_back(max(max_val.back()[i], max_val.back()[i + MASK(k - 1)]));
		max_val.push_back(nxt);
	}
	auto get_max = [&] (int l, int r) {
		int h = __lg(r - l + 1);
		return max(max_val[h][l], max_val[h][r - MASK(h) + 1]);
	};

	vector <vector <int>> queriesAt(N);
	vector <long long> res(Q);
	REP(i, Q) {
		int ma = get_max(L[i], R[i]).se;
		res[i] = 1LL * (R[i] - L[i] + 1) * H[ma];
		queriesAt[ma].push_back(i);
	}

	REP(fl, 2) {
		vector <int> left_child(N, -1), right_child(N, -1);
		REP(i, N) if (~par[i]) (i < par[i] ? left_child[par[i]] : right_child[par[i]]) = i;
		map <int, Line> cost;
		vector <long long> lazy(N);
		vector <int> cnt(N);
		function <void(int, int, int)> dfs = [&] (int u, int prv, int nxt) {
			long long cost_left = 0;
			int l = left_child[u];
			if (~l) {
				dfs(l, prv, u - 1);
				lazy[u] = lazy[l];
				Line x = prev(cost.lower_bound(u))->se;
				cnt[u] = cnt[l];
				cost_left = x.eval(x.len - 1) + lazy[l];
			}
			cost[u] = Line(0, cost_left + H[u] - lazy[u], 1);
			++cnt[u];
			Line f(H[u], cost_left + H[u] + H[u]);

			int r = right_child[u];
			if (~r) {
				dfs(r, u + 1, nxt);
				for (int i: queriesAt[u]) {
					auto [x, l] = *prev(cost.upper_bound(R[i]));
					minimize(res[i], l.eval(R[i] - x) + lazy[r] + 1LL * (u - L[i] + 1) * H[u]);
				}
				lazy[r] += 1LL * (u - prv + 1) * H[u];
				for (auto it = cost.find(u + 1); it != cost.end() && it->fi <= nxt; ) {
					int v = it->fi;
					Line g = it->se;
					long long x = f.eval(f.len + g.len - 1);
					long long y = g.eval(g.len - 1) + lazy[r];
					it = cost.erase(it);
					--cnt[r];
					if (x <= y) {
						f.len += g.len;
					} else {
						int low = 0, high = g.len - 1;
						while (low <= high) {
							int m = low + high >> 1;
							if (f.eval(f.len + m) > g.eval(m) + lazy[r]) high = m - 1;
							else low = m + 1;
						}
						f.len += low;
						cost[v + low] = Line(g.a, g.b + g.a * low, g.len - low);
						++cnt[r];
						break;
					}
				}
				if (f.len) {
					f.b -= lazy[u];
					cost[u + 1] = f;
					++cnt[u];
				}
				if (cnt[u] <= cnt[r]) {
					for (auto it = cost.find(prv); it->fi <= u + f.len; ++it)
						it->se.b += lazy[u] - lazy[r];
					lazy[u] = lazy[r];
				} else {
					for (auto it = cost.find(u + f.len + 1); it != cost.end() && it->fi <= nxt; ++it)
						it->se.b += lazy[r] - lazy[u];
				}
				cnt[u] += cnt[r];
			}
		};
		dfs(root, 0, N - 1);
		root = N - root - 1;
		reverse(ALL(par));
		reverse(ALL(queriesAt));
		REP(i, N) if (~par[i]) par[i] = N - par[i] - 1;
		reverse(ALL(H));
		REP(i, Q) {
			L[i] = N - L[i] - 1;
			R[i] = N - R[i] - 1;
			swap(L[i], R[i]);
		}
	}
	return res;
}

#ifdef LOCAL
#include <cstdio>
#include <cstdlib>
#include <vector>
#include "meetings.h"

namespace {

int read_int() {
	int x;
	if (scanf("%d", &x) != 1) {
		fprintf(stderr, "Error while reading input\n");
		exit(1);
	}
	return x;
}

}  // namespace

int main() {
	file("meetings");
	int N = read_int();
	int Q = read_int();
	std::vector<int> H(N);
	for (int i = 0; i < N; ++i) {
		H[i] = read_int();
	}
	std::vector<int> L(Q), R(Q);
	for (int j = 0; j < Q; ++j) {
		L[j] = read_int();
		R[j] = read_int();
	}

	std::vector<long long> C = minimum_costs(H, L, R);
	cout << "answer:\n";
	for (size_t j = 0; j < C.size(); ++j) {
		printf("%lld\n", C[j]);
	}
	return 0;
}
#endif

Compilation message (stderr)

meetings.cpp: In lambda function:
meetings.cpp:143:20: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  143 |        int m = low + high >> 1;
      |                ~~~~^~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 15 / 15
• Subtask 3: 17 / 17
• Subtask 4: 24 / 24
• Subtask 5: 40 / 40