#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int main() {
ios::sync_with_stdio(0), cin.tie(0);
int m;
ll L, all = 0;
cin >> m >> L;
vector<ll> _a(2 * m + 1), _b(2 * m + 1);
auto a = _a.data() + m, b = _b.data() + m;
for (int i = -m; i <= m; i++) {
cin >> a[i], all += max(0, i) * a[i];
}
if (L < 0) {
L *= -1, all = 0;
for (int i = 1; i <= m; i++) {
swap(a[i], a[-i]), all += i * a[i];
}
}
if (all < L) cout << "impossible\n", exit(0);
ll ans = a[0];
for (int i = -1; i >= -m; i--) {
b[i] = min(a[i], (all - L) / -i);
ans += b[i], L -= b[i] * i, a[i] -= b[i];
}
for (int i = 1; i <= m; i++) {
b[i] = min(a[i], L / i);
ans += b[i], L -= b[i] * i, a[i] -= b[i];
}
int lim = m * L;
vector<int> _f(2 * lim + 1, -1e9);
auto f = _f.data() + lim;
f[0] = 0;
for (int i = -m; i <= m; i++) if (i) {
auto _g = _f;
auto g = _g.data() + lim;
auto tr = [&](int x, int w) {
for (int j = -lim; j <= lim; j++) if (j + x >= -lim && j + x <= lim) {
if (g[j + x] < f[j] + w) g[j + x] = f[j] + w;
}
};
a[i] = min(a[i], 2LL * lim / abs(i));
for (int j = 20; ~j; j--) if ((1 << j) - 1 <= a[i]) {
for (int k = 0; k < j; k++) tr(i * (1 << k), 1 << k);
a[i] -= (1 << j) - 1, tr(i * a[i], a[i]); break;
}
b[i] = min(b[i], 2LL * lim / abs(i));
for (int j = 20; ~j; j--) if ((1 << j) - 1 <= b[i]) {
for (int k = 0; k < j; k++) tr(-i * (1 << k), -1 << k);
b[i] -= (1 << j) - 1, tr(-i * b[i], -b[i]); break;
}
swap(_f, _g);
}
if (f[L] < -1e8) cout << "impossible\n";
else cout << ans + f[L] << "\n";
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Incorrect |
4 ms |
340 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Incorrect |
4 ms |
340 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Incorrect |
4 ms |
340 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Incorrect |
4 ms |
340 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
0 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
0 ms |
212 KB |
Output is correct |
6 |
Incorrect |
4 ms |
340 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |