Submission #530354

#	Time	Username	Problem	Language	Result	Execution time	Memory
530354		abc864197532	Global Warming (CEOI18_glo)	C++17	75 / 100	2070 ms	18808 KiB

glo

#include <bits/stdc++.h>
using namespace std;
#define lli long long int
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define X first
#define Y second
#define pii pair<int,int>
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
void abc() {cout << endl;}
template <typename T, typename ...U> void abc(T i, U ...j) {
	cout << i << ' ', abc(j...);
}
template <typename T> void printv(T l, T r) {
	for (; l != r; ++l)
		cout << *l << " \n"[l + 1 == r];
}
#ifdef Doludu
#define test(x...) abc("[" + string(#x) + "]", x);
#define owo freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout)
#else
#define test(x...) void(0);
#define owo ios::sync_with_stdio(false), cin.tie(0)
#endif
const int N = 400087;

struct BIT {
	int val[N];
	void init() {
		fill(val, val + N, 0);
	}
	void add(int p, int v) {
		p += 5;
		for (int i = p; i < N; i += i & (-i))
			val[i] = max(val[i], v);
	}
	int query(int p) {
		p += 5;
		int ans = 0;
		for (int i = p; i > 0; i -= i & (-i))
			ans = max(ans, val[i]);
		return ans;
	}
} bit1, bit2;


vector <int> a;
int n;

int ask(int x) {
	vector <vector <int>> dp(n, vector <int> (3, 0));
	vector <int> v;
	for (int i : a)
		v.pb(i), v.pb(i + x);
	sort(all(v)), v.resize(unique(all(v)) - v.begin());
	bit1.init(), bit2.init();
	dp[0][0] = 1, dp[0][1] = 1, dp[0][2] = 0;
	int ans = 1;
	for (int i = 0; i < n; ++i) {
		int p = lower_bound(all(v), a[i]) - v.begin();
		int q = lower_bound(all(v), a[i] + x) - v.begin();
		if (i) {
			dp[i][0] = bit1.query(p) + 1;
			dp[i][1] = max(bit1.query(q), bit2.query(q)) + 1;
			dp[i][2] = bit2.query(p) + 1;
		}
		bit1.add(p + 1, dp[i][0]);
		bit2.add(q + 1, dp[i][1]);
		ans = max({ans, dp[i][0], dp[i][1], dp[i][2]});
	}
	return ans;
}

int main () {
	owo;
	int d;
	cin >> n >> d;
	a.resize(n);
	for (int i = 0; i < n; ++i)
		cin >> a[i];
	if (d == 1000000000) {
		vector <int> pre(n + 1), suf(n + 1);
		{
			vector <int> v;
			for (int i = 0; i < n; ++i) {
				if (v.empty() || v.back() < a[i])
					v.pb(a[i]);
				else
					*lower_bound(all(v), a[i]) = a[i];
				pre[i + 1] = v.size();
			}
		}
		for (int &i : a)
			i *= -1;
		{
			vector <int> v;
			for (int i = n - 1; ~i; --i) {
				if (v.empty() || v.back() < a[i])
					v.pb(a[i]);
				else
					*lower_bound(all(v), a[i]) = a[i];
				suf[i] = v.size();
			}
		}
		int ans = 0;
		for (int i = 0; i < n; ++i)
			ans = max(ans, pre[i] + suf[i]);
		cout << ans << endl;
		return 0;
	}
	lli l = 0, r = d + 1;
	while (r - l > 10) {
		lli m1 = (l + l + r) / 3, m2 = (l + r + r) / 3;
		if (ask(m1) < ask(m2))
			l = m1;
		else
			r = m2;
	}
	int ans = 0;
	for (int i = l; i < r; ++i)
		ans = max(ans, ask(i));
	l = -d, r = 1;
	while (r - l > 10) {
		lli m1 = (l + l + r) / 3, m2 = (l + r + r) / 3;
		if (ask(m1) < ask(m2))
			l = m1;
		else
			r = m2;
	}
	for (int i = l; i < r; ++i)
		ans = max(ans, ask(i));
	cout << ans << endl;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 13 / 13
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 17 / 17
• Subtask 7: 0 / 25