#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
const int MOD = (int)1e9 + 7;
const int MAXN = (int)1e5 + 3;
const int infint = (int)1e9 + 3;
const ll inf = (ll)2e18;
ll n, k, t, X[MAXN];
bool make(vector <ll> x, vector <ll> y)
{
if (x[0] < y[0])
return 0;
int ok = 1;
pair<int, int> L, R;
L = {0, 0};
R = {0, 0};
while (ok)
{
ok = 0;
while (L.first + 1 < x.size() && x[L.first + 1] >= y[R.second])
{
ok = 1;
if (x[++L.first] > x[L.second])
L.second = L.first;
}
while (R.first + 1 < y.size() && y[R.first + 1] <= x[L.second])
{
ok = 1;
if (y[++R.first] < y[R.second])
R.second = R.first;
}
}
return L.first + 1 == x.size() && R.first + 1 == y.size();
}
bool check(int s)
{
vector <ll> x, y;
for (ll i = k; i >= 0; i--)
x.push_back(X[i] - 1LL * 2 * s * t * i);
for (ll i = k; i < n; i++)
y.push_back(X[i] - (1LL * 2 * s * t * i);
if (!make(x, y))
return 0;
reverse(x.begin(), x.end());
reverse(y.begin(), y.end());
if (!make(x, y))
return 0;
return 1;
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
cin >> n >> k >> t;
k--;
for (ll i = 0; i < n; i++)
cin >> X[i];
int L = 0, R = infint;
while (L < R)
{
ll mid = (L + R) >> 1;
if (check(mid))
R = mid;
else
L = mid + 1;
}
cout << L;
}
Compilation message
sparklers.cpp: In function 'bool make(std::vector<long long int>, std::vector<long long int>)':
sparklers.cpp:21:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
while (L.first + 1 < x.size() && x[L.first + 1] >= y[R.second])
~~~~~~~~~~~~^~~~~~~~~~
sparklers.cpp:27:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
while (R.first + 1 < y.size() && y[R.first + 1] <= x[L.second])
~~~~~~~~~~~~^~~~~~~~~~
sparklers.cpp:34:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
return L.first + 1 == x.size() && R.first + 1 == y.size();
~~~~~~~~~~~~^~~~~~~~~~~
sparklers.cpp:34:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
return L.first + 1 == x.size() && R.first + 1 == y.size();
~~~~~~~~~~~~^~~~~~~~~~~
sparklers.cpp: In function 'bool check(int)':
sparklers.cpp:43:46: error: expected ')' before ';' token
y.push_back(X[i] - (1LL * 2 * s * t * i);
^
