#include<bits/stdc++.h>
using namespace std;
typedef long double ld;
typedef long long ll;
#define rep(a, b) for(int a = 0; a < (b); ++a)
#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
const ll INF=1e9+7;
const int LIM=1e5+7;
ll T[LIM], n, k, t;
vector<ll>A, B;
vector<pair<ll,ll>>calc(vector<ll>T) {
ll m=T.size()-1;
vector<pair<ll,ll>>P;
for(int i=(int)T.size()-1; i>=0; --i) {
pair<ll,ll>x={max(0ll, -T[i]), T[i]};
while(P.size()>0 && x.nd<0) {
pair<ll,ll>y={max(x.st, P.back().st-x.nd), x.nd+P.back().nd};
P.pop_back();
x=y;
}
P.pb(x);
}
reverse(all(P));
return P;
}
bool check(ll x) {
vector<ll>X, Y;
for(auto i : A) X.pb(2*x*t-i);
for(auto i : B) Y.pb(2*x*t-i);
vector<pair<ll,ll>>P=calc(X), Q=calc(Y);
ll l1=0, l2=0, akt=0;
while(l1<P.size() && l2<Q.size()) {
if(P[l1].st>akt && Q[l2].st>akt) return false;
if(P[l1].st<=akt && P[l1].nd>=0) {
akt+=P[l1].nd;
++l1;
} else if(Q[l2].st<=akt && Q[l2].nd>=0) {
akt+=Q[l2].nd;
++l2;
} else break;
}
while(l1<P.size()) {
if(P[l1].st>akt) return false;
akt+=P[l1].nd;
++l1;
}
while(l2<Q.size()) {
if(Q[l2].st>akt) return false;
akt+=Q[l2].nd;
++l2;
}
return true;
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> n >> k >> t;
rep(i, n) cin >> T[i];
rep(i, k-1) A.pb(T[i+1]-T[i]);
for(int i=n-1; i>=k; --i) B.pb(T[i]-T[i-1]);
reverse(all(A));
reverse(all(B));
ll po=0, ko=INF;
while(po<ko) {
ll sr=(po+ko)/2;
if(check(sr)) ko=sr; else po=sr+1;
}
cout << po << '\n';
}
Compilation message
sparklers.cpp: In function 'std::vector<std::pair<long long int, long long int> > calc(std::vector<long long int>)':
sparklers.cpp:15:6: warning: unused variable 'm' [-Wunused-variable]
15 | ll m=T.size()-1;
| ^
sparklers.cpp: In function 'bool check(ll)':
sparklers.cpp:35:11: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
35 | while(l1<P.size() && l2<Q.size()) {
| ~~^~~~~~~~~
sparklers.cpp:35:26: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
35 | while(l1<P.size() && l2<Q.size()) {
| ~~^~~~~~~~~
sparklers.cpp:45:11: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
45 | while(l1<P.size()) {
| ~~^~~~~~~~~
sparklers.cpp:50:11: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
50 | while(l2<Q.size()) {
| ~~^~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |