Submission #953863

#	Time	Username	Problem	Language	Result	Execution time	Memory
953863		PM1	Uplifting Excursion (BOI22_vault)	C++17	100 / 100	1357 ms	3664 KiB

vault

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define fr first
#define sc second
const ll mxn=305;
ll m,a[mxn*2],l,sum,ans,num;
vector<pair<ll,ll>>v;
ll dp[2][mxn*mxn*2];
void add(ll tedad,ll x,ll z){
	tedad=(min(tedad,2*m));
	for(ll i=1;i<=tedad;i*=2){
		v.push_back({i*x,z*i});
		tedad-=i;
	}
	if(tedad>0)
		v.push_back({tedad*x,z*tedad});
}
void solve(){
	for(ll i=m;i>=0;i--){
		ans+=a[i];
		num+=a[i]*(i-m);
		add(a[i],-(i-m),-1);
	}
	ll i=m+1;
	for(;i<m*2+1;i++){
		if(num>l)break;
		if(num+a[i]*(i-m)<=l){
			ans+=a[i];
			num+=a[i]*(i-m);
			add(a[i],-(i-m),-1);
			continue;
		}
		ll x=l-num;
		x=x/(i-m);
		x=min(x,a[i]);
		num+=(i-m)*x;
		ans+=x;
		add(x,-(i-m),-1);
		add(a[i]-x,i-m,1);
		i++;
		break;
	}
	for(;i<m*2+1;i++){
		add(a[i],(i-m),1);
	}

}
int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	cin>>m>>l;
	ll hh=0,hhh=0;
	for(ll i=0;i<m*2+1;i++){
		cin>>a[i];
		sum+=(i-m)*a[i];
		if(i-m>0)hh+=(i-m)*a[i];
		else hhh+=(i-m)*a[i];
	}
	if(l>hh || l<hhh){
		cout<<"impossible";
		return 0;
	}
	if(sum<l){
		for(int i=1;i<=m;i++)
			swap(a[i+m],a[m-i]);
		l*=-1;
		sum*=-1;
	}
	solve();

	for(ll i=0;i<=2*m*m;i++)dp[1][i]=-1e18;
	dp[1][m*m]=0;
	for(ll i=0;i<v.size();i++){
		ll x=v[i].fr,y=v[i].sc;
		ll z=i&1;
		for(ll j=0;j<=2*m*m;j++){
			if(j-x>=0 && j-x<=2*m*m && dp[z^1][j-x]!=-1e18)
				dp[z][j]=max(dp[z^1][j],dp[z^1][j-x]+y);
			else
				dp[z][j]=dp[z^1][j];
		}
	}
	ll x=v.size()&1;
	x^=1;
	l-=num;
	if( l>m*m || l<-m*m ||dp[x][l+m*m]==-1e18 || ans+dp[x][l+m*m]<0){
		cout<<"impossible";
		return 0;
	}
	cout<<ans+dp[x][l+m*m];
	return 0;
}

Compilation message (stderr)

vault.cpp: In function 'int main()':
vault.cpp:75:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   75 |  for(ll i=0;i<v.size();i++){
      |             ~^~~~~~~~~

• 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: 10 / 10