Submission #836256

#	Time	Username	Problem	Language	Result	Execution time	Memory
836256		Sohsoh84	Global Warming (CEOI18_glo)	C++17	0 / 100	70 ms	9332 KiB

glo

// Wounds should become scars but I'm cracked instead U+1FAE0
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> pll;

#define all(x)			(x).begin(),(x).end()
#define X			first
#define Y			second
#define sep			' '
#define endl			'\n'
#define debug(x)		cerr << #x << ": " <<  x << endl;

const ll MAXN = 1e6 + 10;

int pre_dp[MAXN], suff_dp[MAXN], n, fen[MAXN], A[MAXN];
vector<int> comp_vec;

inline void update(int ind, int val) {
	for (++ind; ind < MAXN; ind += ind & -ind) 
		fen[ind] = max(fen[ind], val);
}

inline int query(int ind) {
	int ans = 0;
	for (++ind; ind > 0; ind -= ind & -ind)
		ans = max(ans, fen[ind]);

	return ans;
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> A[i];
		comp_vec.push_back(A[i]);
	}

	sort(all(comp_vec));
	for (int i = 1; i <= n; i++)
		A[i] = lower_bound(all(comp_vec), A[i]) - comp_vec.begin() + 1;

	for (int i = 1; i <= n; i++) {
		pre_dp[i] = query(A[i] - 1) + 1;
		update(A[i], pre_dp[i]);
		pre_dp[i] = max(pre_dp[i], pre_dp[i - 1]);
	}

	memset(fen, 0, sizeof fen);
	for (int i = n; i > 0; i--) {
		suff_dp[i] = query(n - A[i] - 1) + 1;
		update(n - A[i], suff_dp[i]);
		suff_dp[i] = max(suff_dp[i], suff_dp[i + 1]);
	}

	int ans = pre_dp[n];
	for (int i = 1; i < n; i++)
		ans = max(ans, pre_dp[i] + suff_dp[i + 1]);
	
	cout << ans << endl;
	return 0;
}

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