Submission #804827

#	Time	Username	Problem	Language	Result	Execution time	Memory
804827		flappybird	Cultivation (JOI17_cultivation)	C++17	65 / 100	2056 ms	5988 KiB

cultivation

#include <bits/stdc++.h>
#include <cassert>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2,fma")
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
#define MAX 660
#define MAXS 20
#define INF 20000000000020
#define bb ' '
#define ln '\n'
#define Ln '\n'
#define MOD 1000000007
ll H, W;
int N;
pll arr[MAX];
ll ans = INF;
int st[MAX * 2], en[MAX * 2];
ll U[MAX], D[MAX], UD[MAX];
ll A[MAX][MAX], B[MAX][MAX], C[MAX][MAX];
typedef pair<ll, int> pli;
deque<pli> up, down, su;
ll ys[MAX * 2];
bool test(ll d) {
	if (d <= 0) return false;
	int i, j;
	int p1, p2;
	p1 = p2 = 1;
	int X = 0;
	while (p1 <= N || p2 <= N) {
		ll x;
		if (p1 > N) x = arr[p2].second + d;
		else if (p2 > N) x = arr[p1].second;
		else x = min(arr[p1].second, arr[p2].second + d);
		ys[X++] = x;
		while (p1 <= N && arr[p1].second == x) p1++;
		while (p2 <= N && arr[p2].second + d == x) p2++;
	}
	for (i = 0; i < X; i++) U[i] = D[i] = UD[i] = 0, st[i] = en[i] = 0;
	for (i = 1; i <= N; i++) {
		int l, r;
		l = lower_bound(ys, ys + X, arr[i].second) - ys;
		r = lower_bound(ys, ys + X, arr[i].second + d) - ys;
		st[l]++;
		en[r]++;
	}
	int il, ir;
	il = ir = 0;
	for (i = 0; i < X; i++) {
		ir += st[i];
		il += en[i];
		if (il == ir) {
			UD[i] = INF;
			continue;
		}
		U[i] = A[il + 1][ir];
		D[i] = B[il + 1][ir];
		UD[i] = C[il + 1][ir];
	}
	up.clear();
	down.clear();
	su.clear();
	ll mn = INF;
	j = 0;
	for (i = 0; i < X - 1; i++) {
		while (up.size() && up.back().first <= U[i]) up.pop_back();
		up.emplace_back(U[i], i);
		while (down.size() && down.back().first <= D[i]) down.pop_back();
		down.emplace_back(D[i], i);
		while (su.size() && su.back().first <= UD[i]) su.pop_back();
		su.emplace_back(UD[i], i);
		while (j + 1 <= i && ys[i + 1] - ys[j + 1] >= W) j++;
		while (up.size() && up.front().second < j) up.pop_front();
		while (down.size() && down.front().second < j) down.pop_front();
		while (su.size() && su.front().second < j) su.pop_front();
		if (ys[i + 1] - ys[j] >= W) mn = min(mn, max(0ll + up.front().first + down.front().first, (ll)su.front().first));
	}
	if (mn >= INF) return false;
	ans = min(ans, mn + d - 1);
	return true;
}
signed main() {
	ios::sync_with_stdio(false), cin.tie(0);
	cin >> H >> W >> N;
	int i, j, k;
	vector<ll> ls;
	ls.push_back(W);
	for (i = 1; i <= N; i++) cin >> arr[i].first >> arr[i].second;
	for (i = 1; i <= N; i++) {
		for (j = i + 1; j <= N; j++) ls.push_back(W - abs(arr[j].second - arr[i].second));
		for (j = i + 1; j <= N; j++) ls.push_back(abs(arr[j].second - arr[i].second));
		for (j = i + 1; j <= N; j++) ls.push_back(abs(arr[j].second - arr[i].second) + W);
		ls.push_back(arr[i].second);
		ls.push_back(arr[i].second + 1);
		ls.push_back(W - arr[i].second);
		ls.push_back(W - arr[i].second + 1);
	}
	sort(arr + 1, arr + N + 1, [&](pii p1, pii p2) {return p1.second < p2.second; });
	for (i = 1; i <= N; i++) {
		vector<ll> v;
		A[i][i] = arr[i].first - 1;
		B[i][i] = H - arr[i].first;
		v.push_back(arr[i].first);
		for (j = i + 1; j <= N; j++) {
			v.insert(lower_bound(v.begin(), v.end(), arr[j].first), arr[j].first);
			for (k = 0; k + 1 < v.size(); k++) C[i][j] = max(C[i][j], v[k + 1] - v[k] - 1);
			A[i][j] = v[0] - 1;
			B[i][j] = H - v.back();
		}
	}
	sort(ls.begin(), ls.end());
	ls.erase(unique(ls.begin(), ls.end()), ls.end());
	reverse(ls.begin(), ls.end());
	for (auto v : ls) if (!test(v)) break;
	cout << ans << ln;
}

Compilation message (stderr)

cultivation.cpp: In function 'int main()':
cultivation.cpp:110:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  110 |    for (k = 0; k + 1 < v.size(); k++) C[i][j] = max(C[i][j], v[k + 1] - v[k] - 1);
      |                ~~~~~~^~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 15
• Subtask 4: 30 / 30
• Subtask 5: 20 / 20
• Subtask 6: 0 / 20