#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;
typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;
#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)
#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 100001;
int N,K,T,mid;
vi X;
ld dp[1000][1000][2];
void mn(ld& a, ld b) { a = min(a,b); }
ld getTi(ld a, ld b) { return (b-a)/2/mid; }
// k = 0:
// X[i-1]+t*mid
// currently at X[i]+t*mid
// X[j]-t*mid
// X[j+1]-t*mid
void balance(int i, int j) {
ld t = dp[i][j][0], lef = (ld)(j-i+1)*T-t;
if (t < INF && lef >= getTi(X[i]+t*mid,X[j]-t*mid)) mn(dp[i][j][1],t+getTi(X[i]+t*mid,X[j]-t*mid));
t = dp[i][j][1], lef = (ld)(j-i+1)*T-t;
if (t < INF && lef >= getTi(X[i]+t*mid,X[j]-t*mid)) mn(dp[i][j][0],t+getTi(X[i]+t*mid,X[j]-t*mid));
}
void ad(int i, int j) {
ld t = dp[i][j][0], lef = (ld)(j-i+1)*T-t;
if (t < INF && i && lef >= getTi(X[i-1],X[i])) mn(dp[i-1][j][0],dp[i][j][0]+getTi(X[i-1],X[i]));
t = dp[i][j][1], lef = (ld)(j-i+1)*T-t;
if (t < INF && j < N-1 && lef >= getTi(X[j],X[j+1])) mn(dp[i][j+1][1],dp[i][j][1]+getTi(X[j],X[j+1]));
}
bool ok() {
F0Rd(i,K+1) FOR(j,K,N) F0R(k,2) dp[i][j][k] = INF;
dp[K][K][0] = dp[K][K][1] = 0;
F0Rd(i,K+1) FOR(j,K,N) balance(i,j), ad(i,j);
return min(dp[0][N-1][0],dp[0][N-1][1]) != INF;
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> N >> K >> T; X.resize(N); K--;
F0R(i,N) cin >> X[i];
int lo = 0, hi = MOD;
while (lo < hi) {
mid = (lo+hi)/2;
if (ok()) hi = mid;
else lo = mid+1;
}
cout << lo;
}
/* Look for:
* the exact constraints (multiple sets are too slow for n=10^6 :( )
* special cases (n=1?)
* overflow (ll vs int?)
* array bounds
* if you have no idea just guess the appropriate well-known algo instead of doing nothing :/
*/
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
376 KB |
Output is correct |
| 2 |
Correct |
2 ms |
380 KB |
Output is correct |
| 3 |
Correct |
2 ms |
492 KB |
Output is correct |
| 4 |
Correct |
2 ms |
624 KB |
Output is correct |
| 5 |
Correct |
2 ms |
628 KB |
Output is correct |
| 6 |
Correct |
3 ms |
680 KB |
Output is correct |
| 7 |
Correct |
2 ms |
680 KB |
Output is correct |
| 8 |
Correct |
2 ms |
680 KB |
Output is correct |
| 9 |
Correct |
3 ms |
732 KB |
Output is correct |
| 10 |
Correct |
2 ms |
784 KB |
Output is correct |
| 11 |
Correct |
3 ms |
784 KB |
Output is correct |
| 12 |
Correct |
2 ms |
844 KB |
Output is correct |
| 13 |
Correct |
3 ms |
844 KB |
Output is correct |
| 14 |
Correct |
3 ms |
844 KB |
Output is correct |
| 15 |
Correct |
2 ms |
844 KB |
Output is correct |
| 16 |
Correct |
3 ms |
844 KB |
Output is correct |
| 17 |
Correct |
3 ms |
844 KB |
Output is correct |
| 18 |
Correct |
2 ms |
844 KB |
Output is correct |
| 19 |
Incorrect |
3 ms |
844 KB |
Output isn't correct |
| 20 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
376 KB |
Output is correct |
| 2 |
Correct |
2 ms |
380 KB |
Output is correct |
| 3 |
Correct |
2 ms |
492 KB |
Output is correct |
| 4 |
Correct |
2 ms |
624 KB |
Output is correct |
| 5 |
Correct |
2 ms |
628 KB |
Output is correct |
| 6 |
Correct |
3 ms |
680 KB |
Output is correct |
| 7 |
Correct |
2 ms |
680 KB |
Output is correct |
| 8 |
Correct |
2 ms |
680 KB |
Output is correct |
| 9 |
Correct |
3 ms |
732 KB |
Output is correct |
| 10 |
Correct |
2 ms |
784 KB |
Output is correct |
| 11 |
Correct |
3 ms |
784 KB |
Output is correct |
| 12 |
Correct |
2 ms |
844 KB |
Output is correct |
| 13 |
Correct |
3 ms |
844 KB |
Output is correct |
| 14 |
Correct |
3 ms |
844 KB |
Output is correct |
| 15 |
Correct |
2 ms |
844 KB |
Output is correct |
| 16 |
Correct |
3 ms |
844 KB |
Output is correct |
| 17 |
Correct |
3 ms |
844 KB |
Output is correct |
| 18 |
Correct |
2 ms |
844 KB |
Output is correct |
| 19 |
Incorrect |
3 ms |
844 KB |
Output isn't correct |
| 20 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
376 KB |
Output is correct |
| 2 |
Correct |
2 ms |
380 KB |
Output is correct |
| 3 |
Correct |
2 ms |
492 KB |
Output is correct |
| 4 |
Correct |
2 ms |
624 KB |
Output is correct |
| 5 |
Correct |
2 ms |
628 KB |
Output is correct |
| 6 |
Correct |
3 ms |
680 KB |
Output is correct |
| 7 |
Correct |
2 ms |
680 KB |
Output is correct |
| 8 |
Correct |
2 ms |
680 KB |
Output is correct |
| 9 |
Correct |
3 ms |
732 KB |
Output is correct |
| 10 |
Correct |
2 ms |
784 KB |
Output is correct |
| 11 |
Correct |
3 ms |
784 KB |
Output is correct |
| 12 |
Correct |
2 ms |
844 KB |
Output is correct |
| 13 |
Correct |
3 ms |
844 KB |
Output is correct |
| 14 |
Correct |
3 ms |
844 KB |
Output is correct |
| 15 |
Correct |
2 ms |
844 KB |
Output is correct |
| 16 |
Correct |
3 ms |
844 KB |
Output is correct |
| 17 |
Correct |
3 ms |
844 KB |
Output is correct |
| 18 |
Correct |
2 ms |
844 KB |
Output is correct |
| 19 |
Incorrect |
3 ms |
844 KB |
Output isn't correct |
| 20 |
Halted |
0 ms |
0 KB |
- |
