Submission #574304

#	Time	Username	Problem	Language	Result	Execution time	Memory
574304		8e7	Uplifting Excursion (BOI22_vault)	C++17	0 / 100	4674 ms	35540 KiB

vault

//Challenge: Accepted
#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
#ifdef zisk
void debug(){cout << endl;}
template<class T, class ... U> void debug(T a, U ... b){cout << a << " ", debug(b...);}
template<class T> void pary(T l, T r) {
	while (l != r) cout << *l << " ", l++;
	cout << endl;
}
#else
#define debug(...) 0
#define pary(...) 0
#endif
#define ll long long
#define maxn 9000005
#define pii pair<int, int>
#define ff first
#define ss second
#define io ios_base::sync_with_stdio(0);cin.tie(0);
const int inf = 1<<30;
int dp[maxn];
int main() {
	io
	int m;
	ll L;
	cin >> m >> L;
	vector<ll> a(2*m+1), ex(2*m+1);	
	ll mins = 0, ans = 0;
	for (int i = 0;i < 2*m+1;i++) {
		cin >> a[i];
		if (i == m) ans += a[i], a[i] = 0;
	}
	for (int i = m+1;i < 2*m+1;i++) {
		ll p = min(a[i], L / (i-m));
		ans += p;
		L -= p * (i-m);
		a[i] -= p;

		ex[i] = min(a[i], (ll)m);
		ex[2 * m - i] = min(p,(ll)m);
	}
	for (int i = 0;i < 2 * m+1;i++) {
		if (i < m) mins += ex[i] * (i - m);
	}
	for (int i = 0;i < maxn;i++) dp[i] = -inf;	

	dp[-mins] = 0;
	for (int i = 0;i < 2*m+1;i++) {
		int d = i - m;
		if (i - m == 0) continue;
		if (i - m > 0) {
			for (int j = 0;j < d;j++) {
				deque<int> deq;
				for (int k = j;k < maxn;k += d) {
					while (deq.size() && (k - deq.front())/d > ex[i]) deq.pop_front();
					if (deq.size()) dp[k] = max(dp[k], dp[deq.front()] + (k - deq.front()) / d);	
					while (deq.size() && dp[k] >= dp[deq.back()] + (k - deq.back())/d) deq.pop_back();
					deq.push_back(k);
				}
			}
		} else {
			for (int j = 0;j < -d;j++) {
				deque<int> deq;
				for (int k = maxn-1-j;k >= 0;k += d) {
					while (deq.size() && (k - deq.front())/d > ex[i]) deq.pop_front();
					if (deq.size()) dp[k] = max(dp[k], dp[deq.front()] - (k - deq.front()) / d);	
					while (deq.size() && dp[k] >= dp[deq.back()] - (k - deq.back())/d) deq.pop_back();
					deq.push_back(k);
				}
			}
		}
	}
	if (L - mins >= maxn || L - mins < 0 || dp[L - mins] < -maxn) cout << "impossible\n";
	else cout << dp[L - mins]+ans << "\n";
}

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