#include<bits/stdc++.h>
using namespace std;
const long long INF = 1e18;
const int maxn = 305;
long long A[2*maxn], inp[2*maxn];
int bs_A[2*maxn][65];
vector<pair<int, long long>> g[65][maxn];
long long dp[4*maxn*maxn];
long long tmp[4*maxn*maxn];
long long mx(const long long &a, const long long &b){return a > b ? a : b;}
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
int m;
long long L;
cin >> m >> L;
for(int i = 0; i <= 2*m; i++)cin >> A[i];
if(L < 0){
L*=-1;
for(int i = 1; i <= m; i++)swap(A[m-i], A[m+i]);
}
for(int i = 0; i <= 2*m; i++){
if(i == m)continue;
for(int j = 0; j <= 60; j++){
if(A[i] == 0)break;
bs_A[i][j] = A[i]&1 ? 1 : 2;
A[i] = (A[i]-1)/2;
}
}
for(int b = 0; b <= 60; b++){
for(int i = 1; i <= m; i++){
map<int, long long> mp;
for(int p_val = 0; p_val <= bs_A[m+i][b]; p_val++){
for(int n_val = 0; n_val <= bs_A[m-i][b]; n_val++){
mp[(p_val - n_val)*i] = max<long long>(mp[(p_val - n_val)*i], p_val + n_val);
}
}
for(auto v: mp)g[b][i].push_back({v.first, v.second<<b});
}
}
int sum = m*(m+1)*2;
for(int i = 0; i <= 2*sum; i++)dp[i] = -INF;
dp[sum] = 0;
for(int b = 0; b <= 60; b++){
for(int i = 1; i <= m; i++){
for(int j = 0; j <= 2*sum; j++)tmp[j] = -INF;
for(auto v: g[b][i])for(int j = 0; j <= 2*sum; j++)tmp[j + v.first] = mx(tmp[j + v.first], dp[j] + v.second);
memcpy(dp, tmp, sizeof(dp));
}
for(int j = 0; j <= 2*sum; j++)tmp[j] = -1;
for(int i = 0; i <= 2*sum; i++){
if(((i&1)^(sum&1)) != ((L>>b)&1))continue;
int ri = i - sum, pos;
if(ri < 0)pos = (ri-1)/2 + sum;
else pos = ri/2 + sum;
assert(pos >= 0 && pos <= 2*sum);
tmp[pos] = max(tmp[pos], dp[i]);
}
for(int i = 0; i <= 2*sum; i++)dp[i] = tmp[i];
}
if(dp[sum] == -1)cout << "impossible";
else cout << dp[sum] + A[m];
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
15 ms |
4440 KB |
Output is correct |
2 |
Incorrect |
20 ms |
4440 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
15 ms |
4440 KB |
Output is correct |
2 |
Incorrect |
20 ms |
4440 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
73 ms |
4576 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
73 ms |
4576 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
73 ms |
4576 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
15 ms |
4440 KB |
Output is correct |
2 |
Incorrect |
20 ms |
4440 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
73 ms |
4576 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
15 ms |
4440 KB |
Output is correct |
2 |
Incorrect |
20 ms |
4440 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
73 ms |
4576 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
15 ms |
4440 KB |
Output is correct |
2 |
Incorrect |
20 ms |
4440 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |