Submission #790950

#	Time	Username	Problem	Language	Result	Execution time	Memory
790950		acatmeowmeow	Global Warming (CEOI18_glo)	C++11	100 / 100	416 ms	41424 KiB

glo

#include <bits/stdc++.h>

using namespace std;

#define int long long 

const int N = 2e5;
int n, x, arr[N + 5], tree[2][3*4*N + 5];

void update(int layer, int v, int tl, int tr, int k, int x) {
	if (tl == tr) tree[layer][v] = max(tree[layer][v], x);
	else {
		int tm = (tl + tr)/2;
		if (k <= tm) update(layer, v*2, tl, tm, k, x);
		else update(layer, v*2 + 1, tm + 1, tr, k, x);
		tree[layer][v] = max(tree[layer][v*2], tree[layer][v*2 + 1]);
	}
}

int query(int layer, int v, int tl, int tr, int l, int r) {
	if (l > r) return 0;
	else if (tl == l && tr == r) return tree[layer][v];
	else {
		int tm = (tl + tr)/2;
		return max(query(layer, v*2, tl, tm, l, min(tm, r)), query(layer, v*2 + 1, tm + 1, tr, max(l, tm + 1), r));
	}
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cin >> n >> x;
	for (int i = 1; i <= n; i++) cin >> arr[i];
	vector<int> mp;
	for (int i = 1; i <= n; i++) mp.push_back(arr[i] - 1), mp.push_back(arr[i]), mp.push_back(arr[i] + x - 1);
	sort(mp.begin(), mp.end());
	mp.erase(unique(mp.begin(), mp.end()), mp.end());
	auto index = [&](int pos) { return lower_bound(mp.begin(), mp.end(), pos) - mp.begin() + 1; };
	int ans = 0, sz = mp.size();
	for (int i = 1; i <= n; i++) {
		int p = index(arr[i] - 1), cur = index(arr[i]), nex = index(arr[i] + x - 1);
		int res0 = query(0, 1, 1, sz, 1, p) + 1; 
		int res1 = max(query(1, 1, 1, sz, 1, p) + 1, query(0, 1, 1, sz, 1, nex) + 1);
		update(0, 1, 1, sz, cur, res0);
		update(1, 1, 1, sz, cur, res1);
		ans = max({ans, res0, res1});
	}
	cout << ans << '\n';
	return 0;
}

• 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: 25 / 25