Submission #456843

#	Time	Username	Problem	Language	Result	Execution time	Memory
456843		pavement	Candies (JOI18_candies)	C++17	0 / 100	2 ms	460 KiB

candies

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#ifdef _WIN32
#define getchar_unlocked _getchar_nolock
#endif
#define int long long
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define ppb pop_back
#define eb emplace_back
#define g0(a) get<0>(a)
#define g1(a) get<1>(a)
#define g2(a) get<2>(a)
#define g3(a) get<3>(a)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef double db;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef tuple<int, int, int> iii;
typedef tuple<int, int, int, int> iiii;
typedef tree<ii, null_type, less<ii>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

int N, tot, A[200005], P[200005][2];
set<iii> s1, r1;
set<tuple<ii, int, int> > s2;

ii rmq(int l, int r) {
	ii ret = mp(LLONG_MIN, LLONG_MIN);
	for (int i = l; i <= r; i++) ret = max(ret, mp(A[i], i));
	return ret;
}

void tks1() {
	vector<set<iii>::iterator> td;
	assert(!s1.empty());
	auto [v, l, r] = *s1.rbegin();
	assert(l != 1 && r != N);
	s1.erase(--s1.end());
	tot += v;
	int newl = l - 1, newr = r + 1;
	auto it = r1.find(mt(l, r, v));
	assert(it != r1.end());
	++it;
	if (it != r1.end() && g0(*it) == newr + 2) {
		newr = g1(*it);
		td.pb(it);
		if (s1.find(mt(g2(*it), g0(*it), g1(*it))) != s1.end()) s1.erase(mt(g2(*it), g0(*it), g1(*it)));
	}
	--it;
	if (it != r1.begin()) {
		--it;
		if (g1(*it) == newl - 2) {
			newl = g0(*it);
			td.pb(it);
			if (s1.find(mt(g2(*it), g0(*it), g1(*it))) != s1.end()) s1.erase(mt(g2(*it), g0(*it), g1(*it)));
		}
		++it;
	}
	for (auto i : td) r1.erase(i);
	assert((newl & 1) == (newr & 1));
	if (newl == 1 || newr == N) {
		r1.emplace(newl, newr, -1ll);
	} else {
		int nv = (P[newr + 1][(newr + 1) & 1] - P[newl - 2][(newr + 1) & 1]) - (P[newr + 1][newr & 1] - P[newl - 2][newr & 1]);
		s1.emplace(nv, newl, newr);
		r1.emplace(newl, newr, nv);
	}
}

void tks2() {
	vector<set<iii>::iterator> td;
	assert(!s2.empty());
	auto [v, l, r] = *s2.rbegin();
	s2.erase(--s2.end());
	tot += v.first;
	if (l <= v.second - 2) {
		s2.emplace(rmq(l, v.second - 2), l, v.second - 2);
	}
	if (v.second + 2 <= r) {
		s2.emplace(rmq(v.second + 2, r), v.second + 2, r);
	}
	int newl = v.second, newr = v.second;
	auto it = r1.lower_bound(mt(newl, 0ll, 0ll));
	if (it != r1.end() && g0(*it) == newr + 2) {
		newr = g1(*it);
		td.pb(it);
		if (s1.find(mt(g2(*it), g0(*it), g1(*it))) != s1.end()) s1.erase(mt(g2(*it), g0(*it), g1(*it)));
	}
	if (it != r1.begin()) {
		--it;
		if (g1(*it) == newl - 2) {
			newl = g0(*it);
			td.pb(it);
			if (s1.find(mt(g2(*it), g0(*it), g1(*it))) != s1.end()) s1.erase(mt(g2(*it), g0(*it), g1(*it)));
		}
	}
	for (auto i : td) r1.erase(i);
	assert((newl & 1) == (newr & 1));
	if (newl == 1 || newr == N) {
		r1.emplace(newl, newr, -1ll);
	} else {
		int nv = (P[newr + 1][(newr + 1) & 1] - P[newl - 2][(newr + 1) & 1]) - (P[newr + 1][newr & 1] - P[newl - 2][newr & 1]);
		s1.emplace(nv, newl, newr);
		r1.emplace(newl, newr, nv);
	}
}

main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> N;
	for (int i = 1; i <= N; i++) {
		cin >> A[i];
		P[i][0] = (i & 1 ? 0 : A[i]) + P[i - 1][0];
		P[i][1] = (i & 1 ? A[i] : 0) + P[i - 1][1];
	}
	s2.emplace(rmq(1, N), 1, N);
	for (int i = 1; i <= (N + 1) / 2; i++) {
		if (s1.empty()) {
			tks2();
		} else if (s2.empty()) {
			tks1();
		} else {
			if (g0(*s1.rbegin()) > g0(*s2.rbegin()).first) {
				tks1();
			} else {
				tks2();
			}
		}
		cout << tot << '\n';
	}
}

Compilation message (stderr)

candies.cpp:113:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  113 | main() {
      | ^~~~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 92