#include <bits/stdc++.h>
using namespace std;
typedef long long lint;
typedef pair<lint, lint> pll;
#define fi first
#define se second
const int MAXN = 100010;
const int INF = 1e9 + 5;
lint X[MAXN];
void solve(vector<lint> &v, vector<pll> &r) {
for(auto &a : v) {
pll t = pll(a, max(-a, 0ll));
while(!r.empty() && t.fi < 0) {
t.se = r.back().se - t.fi;
t.fi += r.back().fi;
r.pop_back();
}
if(t.fi >= 0) r.push_back(t);
}
}
int main() {
ios::sync_with_stdio(0); cin.tie(0);
int N, K;
lint T;
cin >> N >> K >> T;
for(int i = 1; i <= N; i++) cin >> X[i];
lint s = 0, e = INF;
while(s < e) {
lint m = (s + e) / 2;
vector<lint> v1, v2;
for(int i = 1; i < K; i++) v1.push_back(2 * T * m - X[i + 1] + X[i]);
for(int i = N; i > K; i--) v2.push_back(2 * T * m - X[i] + X[i - 1]);
lint sum = 0;
for(auto a : v1) sum += a;
for(auto a : v2) sum += a;
//printf("m = %lld\n", m);
if(sum < 0) {
s = m + 1;
continue;
}
vector<pll> r1, r2;
solve(v1, r1);
solve(v2, r2);
/*
printf("v1 : ");
for(auto a : v1) printf("%lld ", a);
printf("\nv2 : ");
for(auto a : v2) printf("%lld ", a);
printf("\nr1 : ");
for(auto a : r1) printf("(%lld, %lld) ", a.fi, a.se);
printf("\nr2 : ");
for(auto a : r2) printf("(%lld, %lld) ", a.fi, a.se);
printf("\n");
*/
lint t = 0;
int p1 = int(r1.size()) - 1, p2 = int(r2.size()) - 1;
while(p1 >= 0 || p2 >= 0) {
if(p2 < 0 || (p1 >= 0 && r1[p1].se < r2[p2].se)) {
if(t < r1[p1].se) break;
t += r1[p1--].fi;
}
else {
if(t < r2[p2].se) break;
t += r2[p2--].fi;
}
}
if(p1 >= 0 || p2 >= 0) s = m + 1;
else e = m;
}
cout << s << "\n";
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
508 KB |
Output is correct |
| 2 |
Correct |
2 ms |
376 KB |
Output is correct |
| 3 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
508 KB |
Output is correct |
| 2 |
Correct |
2 ms |
376 KB |
Output is correct |
| 3 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
508 KB |
Output is correct |
| 2 |
Correct |
2 ms |
376 KB |
Output is correct |
| 3 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
