#include "bits/stdc++.h"
#define int long long
#define dq deque<int>
using namespace std;
const long long INF = 1ll << 35;
const int N = 1.2e5;
int n, k, t, x[N];
dq L, R;
void ps(dq &v) {
v.push_front(0);
for (int i = 1; i < v.size(); i++) v[i] += v[i - 1];
}
array<int, 3> find(const dq &v) {
int mn = v[0];
for (int i = 1; i < v.size(); i++) {
int u = v[i];
mn = min(mn, u);
if (u >= v[0]) return {u, mn, 1};
}
return {0, 0, 0};
}
bool solve(array<dq, 2> v, int d = 0) {
if (v[0][0] + v[1][0] < 0 || v[1].back() + v[0].back() < 0) return false;
array<int, 3> A[2];
A[0] = find(v[0]);
A[1] = find(v[1]);
while (v[0].size() > 1 || v[1].size() > 1) {
bool flag = false;
for (int k = 0; k < 2; k++) if (A[k][2]) {
if (v[k ^ 1][0] + A[k][1] >= 0) {
v[k].pop_front();
while (v[k][0] != A[k][0]) v[k].pop_front();
A[k] = find(v[k]);
flag = true;
}
}
if (flag) continue;
else if (A[0][2] && A[1][2]) return false;
if (!A[0][2] && !A[1][2]) {
for (int k = 0; k < 2; k++) reverse(v[k].begin(), v[k].end());
return solve(v, d + 1);
}
return false;
}
return true;
}
bool check(int O) {
int s = O * 2 * t;
dq l = L, r = R;
for (auto &u: l) u = s - u;
for (auto &u: r) u = s - u;
ps(l), ps(r);
return solve(array<dq, 2>{l, r});
}
signed main() {
ios::sync_with_stdio(0), cin.tie(0);
cin >> n >> k >> t, k--;
for (int i = 0; i < n; i++) cin >> x[i];
for (int i = 0; i < k; i++) L.push_back(x[i + 1] - x[i]);
reverse(L.begin(), L.end());
for (int i = k + 1; i < n; i++) R.push_back(x[i] - x[i - 1]);
int l = 0;
for (int i = 35; i >= 0; i--) if (!check(1ll << i | l)) l |= 1 << i;
cout << l + 1;
}
Compilation message
sparklers.cpp: In function 'void ps(std::deque<long long int>&)':
sparklers.cpp:12:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::deque<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
12 | for (int i = 1; i < v.size(); i++) v[i] += v[i - 1];
| ~~^~~~~~~~~~
sparklers.cpp: In function 'std::array<long long int, 3> find(const std::deque<long long int>&)':
sparklers.cpp:17:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::deque<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
17 | for (int i = 1; i < v.size(); i++) {
| ~~^~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
340 KB |
Output is correct |
| 2 |
Correct |
0 ms |
212 KB |
Output is correct |
| 3 |
Correct |
0 ms |
340 KB |
Output is correct |
| 4 |
Correct |
0 ms |
340 KB |
Output is correct |
| 5 |
Correct |
0 ms |
212 KB |
Output is correct |
| 6 |
Correct |
0 ms |
340 KB |
Output is correct |
| 7 |
Correct |
0 ms |
212 KB |
Output is correct |
| 8 |
Correct |
0 ms |
212 KB |
Output is correct |
| 9 |
Correct |
0 ms |
340 KB |
Output is correct |
| 10 |
Correct |
0 ms |
212 KB |
Output is correct |
| 11 |
Correct |
0 ms |
212 KB |
Output is correct |
| 12 |
Correct |
0 ms |
212 KB |
Output is correct |
| 13 |
Correct |
0 ms |
340 KB |
Output is correct |
| 14 |
Correct |
0 ms |
212 KB |
Output is correct |
| 15 |
Correct |
0 ms |
212 KB |
Output is correct |
| 16 |
Correct |
0 ms |
212 KB |
Output is correct |
| 17 |
Correct |
0 ms |
212 KB |
Output is correct |
| 18 |
Correct |
0 ms |
340 KB |
Output is correct |
| 19 |
Incorrect |
0 ms |
340 KB |
Output isn't correct |
| 20 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
340 KB |
Output is correct |
| 2 |
Correct |
0 ms |
212 KB |
Output is correct |
| 3 |
Correct |
0 ms |
340 KB |
Output is correct |
| 4 |
Correct |
0 ms |
340 KB |
Output is correct |
| 5 |
Correct |
0 ms |
212 KB |
Output is correct |
| 6 |
Correct |
0 ms |
340 KB |
Output is correct |
| 7 |
Correct |
0 ms |
212 KB |
Output is correct |
| 8 |
Correct |
0 ms |
212 KB |
Output is correct |
| 9 |
Correct |
0 ms |
340 KB |
Output is correct |
| 10 |
Correct |
0 ms |
212 KB |
Output is correct |
| 11 |
Correct |
0 ms |
212 KB |
Output is correct |
| 12 |
Correct |
0 ms |
212 KB |
Output is correct |
| 13 |
Correct |
0 ms |
340 KB |
Output is correct |
| 14 |
Correct |
0 ms |
212 KB |
Output is correct |
| 15 |
Correct |
0 ms |
212 KB |
Output is correct |
| 16 |
Correct |
0 ms |
212 KB |
Output is correct |
| 17 |
Correct |
0 ms |
212 KB |
Output is correct |
| 18 |
Correct |
0 ms |
340 KB |
Output is correct |
| 19 |
Incorrect |
0 ms |
340 KB |
Output isn't correct |
| 20 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
340 KB |
Output is correct |
| 2 |
Correct |
0 ms |
212 KB |
Output is correct |
| 3 |
Correct |
0 ms |
340 KB |
Output is correct |
| 4 |
Correct |
0 ms |
340 KB |
Output is correct |
| 5 |
Correct |
0 ms |
212 KB |
Output is correct |
| 6 |
Correct |
0 ms |
340 KB |
Output is correct |
| 7 |
Correct |
0 ms |
212 KB |
Output is correct |
| 8 |
Correct |
0 ms |
212 KB |
Output is correct |
| 9 |
Correct |
0 ms |
340 KB |
Output is correct |
| 10 |
Correct |
0 ms |
212 KB |
Output is correct |
| 11 |
Correct |
0 ms |
212 KB |
Output is correct |
| 12 |
Correct |
0 ms |
212 KB |
Output is correct |
| 13 |
Correct |
0 ms |
340 KB |
Output is correct |
| 14 |
Correct |
0 ms |
212 KB |
Output is correct |
| 15 |
Correct |
0 ms |
212 KB |
Output is correct |
| 16 |
Correct |
0 ms |
212 KB |
Output is correct |
| 17 |
Correct |
0 ms |
212 KB |
Output is correct |
| 18 |
Correct |
0 ms |
340 KB |
Output is correct |
| 19 |
Incorrect |
0 ms |
340 KB |
Output isn't correct |
| 20 |
Halted |
0 ms |
0 KB |
- |
