#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
#define ll long long
int main() {
int n; cin >> n; n = 2 * n + 1;
ll l; cin >> l;
vector<ll> arr(n); for (int i = 0; i < n; ++i) cin >> arr[i];
if (l < 0) reverse(arr.begin(), arr.end()), l = -l;
for (int i = 0; i < n / 2; ++i) arr[n - 1 - i] += arr[i], l += (n / 2 - i) * arr[i], arr[i] = 0;
ll sum = 0;
vector<ll> count(n / 2 + 1); count[0] = arr[n / 2];
for (int i = 1; i <= n / 2; ++i) {
if (sum == l) break;
if (arr[i + n / 2] * i + sum <= l) sum += arr[i + n / 2] * i, swap(count[i], arr[i + n / 2]);
else {
int take = (l - sum) / i;
sum += i * take, count[i] += take, arr[i + n / 2] -= take;
//cout << sum << '\n';
int sum2 = 0;
vector<ll> copy = count, copy2 = arr;
for (int j = i; j > 0; --j) {
while (count[j]) {
if (sum2 >= i + sum - l) break;
--count[j], ++arr[j + n / 2], sum2 += j;
}
if (count[j]) break;
}
if (sum + i - sum2 > l) {
count = copy, arr = copy2;
continue;
}
sum += i - sum2;
++count[i], --arr[i + n / 2];
}
//cout << sum << '\n';
}
if (sum != l) cout << "impossible\n";
else {
ll ans = 0;
for (ll num : count) ans += num;
cout << ans << '\n';
}
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
7 |
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 |
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 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
7 |
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 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
7 |
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 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
7 |
Halted |
0 ms |
0 KB |
- |