Submission #1070973

#	Time	Username	Problem	Language	Result	Execution time	Memory
1070973		AdamGS	Uplifting Excursion (BOI22_vault)	C++17	90 / 100	5064 ms	71988 KiB

vault

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(a, b) for(int a = 0; a < (b); ++a)
#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
const ll INF=1e18+7;
const ll LIM=1e6+7;
vector<int>V[LIM];
ll dp[LIM], dp2[LIM], A[LIM], B[LIM], l[LIM], sz[LIM];
int main() {
	ios_base::sync_with_stdio(0); cin.tie(0);
	ll n, m;
	cin >> n >> m;
	rep(i, n) cin >> A[n-i];
	rep(i, n+1) cin >> B[i];
	ll ans=0;
	rep(i, n+1) ans+=B[i];
	rep(i, n+1) ans+=A[i];
	rep(i, n+1) m+=A[i]*(ll)i;
	rep(i, n+1) m-=B[i]*(ll)i;
	if(m<0) {
		m*=-1;
		rep(i, n+1) swap(A[i], B[i]);
	}
	rep(i, LIM) dp[i]=INF;
	dp[0]=0;
	int ile=1;
	for(ll i=n; i; --i) {
		if(m>=LIM/2) {
			ll p=m-LIM/2;
			p=(p+i-1)/i;
			p=min(p, max(A[i]-300/ile, 0ll));
			A[i]-=p;
			if(A[i]) ++ile;
			dp[0]+=p;
			m-=p*i;	
		}
	}
	if(m>=LIM) {
		cout << "impossible\n";
		return 0;
	}
	for(int i=1; i<=n; ++i) rep(j, LIM/i+1) V[i-1].pb(0);
	rep(xd, 2) {
		for(ll i=1; i<=n; ++i) if(A[i]) {
			rep(j, i) l[j]=sz[j]=0;
			rep(j, LIM) {
				ll p=j%i;
				while(l[p]<sz[p] && (j-V[p][l[p]])/i>A[i]) ++l[p];
				while(sz[p]>0 && dp[j]<=dp[V[p][sz[p]-1]]+(j-V[p][sz[p]-1])/i) {
					--sz[p];
					l[p]=min(l[p], sz[p]);
				}
				dp2[j]=dp[j];
				if(l[p]<sz[p]) dp2[j]=min(dp2[j], dp[V[p][l[p]]]+(j-V[p][l[p]])/i);
				V[p][sz[p]]=j;
				++sz[p];
			}
			rep(j, LIM) dp[j]=dp2[j];
		}
		rep(i, LIM/2) swap(dp[i], dp[LIM-i-1]);
		rep(i, n+1) swap(A[i], B[i]);
	}
	if(dp[m]==INF) {
		cout << "impossible\n";
		return 0;
	}
	cout << ans-dp[m] << '\n';
}

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