#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
#define st first
#define nd second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define ll long long
ll mod=1000000007;
int inf=1000000007;
ll infl=1000000000000000007;
const int M=207;
ll a[2*M];
ll b[2*M];
ll DP[M*M*4];
ll nDP[M*M*4];
void gg()
{
cout<<"impossible";
exit(0);
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int m;
ll l,sum=0,ans=0,act=0;
cin>>m>>l;
for(ll i=-m;i<=m;i++)
{
cin>>a[i+m];
sum+=a[i+m]*i;
}
ans+=a[m];
a[m]=0;
if(sum>=l)
{
for(ll i=-m;i<=m;i++)
{
ll x;
if(i<=0) x=a[i+m];
else x=min(a[i+m],(l-act)/i);
b[-i+m]+=x;
a[i+m]-=x;
ans+=x;
act+=i*x;
}
}
else
{
for(ll i=m;i>=-m;i--)
{
ll x;
if(i>=0) x=a[i+m];
else x=min(a[i+m],(l-act)/i);
b[-i+m]+=x;
a[i+m]-=x;
ans+=x;
act+=x*i;
}
}
for(int i=-2*m*m;i<=2*m*m;i++) DP[i+2*m*m]=-infl;
DP[2*m*m]=0;
for(int i=1;i<=m;i++)
{
for(int j=-2*m*m;j<=2*m*m;j++) nDP[j+2*m*m]=-infl;
for(int l=-2*m*m;l<-2*m*m+i;l++)
{
deque<pair<int,int>>Q;
int c=0;
for(int j=l;j<=2*m*m;j+=i)
{
c++;
while(sz(Q)>0&&Q[0].nd<c-a[i+m]) Q.pop_front();
while(sz(Q)>0&&Q.back().st<DP[j+2*m*m]-c) Q.pop_back();
Q.pb({DP[j+2*m*m]-c,c});
if(sz(Q)>0) nDP[j+2*m*m]=max(nDP[j+2*m*m],Q[0].st+c);
}
Q.clear();
c=0;
for(int j=l;j<=2*m*m;j+=i)
{
c++;
while(sz(Q)>0&&Q[0].nd<c-a[i+m]-b[i+m]) Q.pop_front();
if(c>a[i+m])
{
while(sz(Q)>0&&Q.back().st<DP[j-a[i+m]*i+2*m*m]+c) Q.pop_back();
Q.pb({DP[j-a[i+m]*i+2*m*m]+c,c});
}
if(sz(Q)>0) nDP[j+2*m*m]=max(nDP[j+2*m*m],Q[0].st+a[i+m]-c);
}
}
for(int j=-2*m*m;j<=2*m*m;j++) DP[j+2*m*m]=nDP[j+2*m*m];
}
for(int i=1;i<=m;i++)
{
for(int j=-2*m*m;j<=2*m*m;j++) nDP[j+2*m*m]=-infl;
for(int l=2*m*m;l>2*m*m-i;l--)
{
deque<pair<int,int>>Q;
int c=0;
for(int j=l;j>=-2*m*m;j-=i)
{
c++;
while(sz(Q)>0&&Q[0].nd<c-a[-i+m]) Q.pop_front();
while(sz(Q)>0&&Q.back().st<DP[j+2*m*m]-c) Q.pop_back();
Q.pb({DP[j+2*m*m]-c,c});
if(sz(Q)>0) nDP[j+2*m*m]=max(nDP[j+2*m*m],Q[0].st+c);
}
Q.clear();
c=0;
for(int j=l;j>=-2*m*m;j-=i)
{
while(sz(Q)>0&&Q[0].nd<c-a[-i+m]-b[-i+m]) Q.pop_front();
c++;
if(c>a[-i+m])
{
while(sz(Q)>0&&Q.back().st<DP[j+a[-i+m]*i+2*m*m]+c) Q.pop_back();
Q.pb({DP[j+a[-i+m]*i+2*m*m]+c,c});
}
if(sz(Q)>0) nDP[j+2*m*m]=max(nDP[j+2*m*m],Q[0].st+a[-i+m]-c);
}
}
for(int j=-2*m*m;j<=2*m*m;j++) DP[j+2*m*m]=nDP[j+2*m*m];
}
l-=act;
if(l<-2*m*m||l>2*m*m) gg();
else
{
if(ans+DP[l+2*m*m]<0) gg();
cout<<ans+(ll)DP[l+2*m*m];
}
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |