#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define sp ' '
#define en '\n'
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
using namespace std;
const int N = 2e5 + 2;
const int inf = 2e9;
int a[N], l[N], r[N], dp[N];
vector<int> g[N];
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int n, k;
cin >> n >> k;
for (int i = 1; i <= n; i++) {
cin >> a[i];
a[i] -= k * i;
}
a[n + 1] = -inf;
stack<int> s;
for (int i = 0; i <= n + 1; i++) {
while (!s.empty() && a[s.top()] < a[i]) s.pop();
if (!s.empty()) l[i] = s.top();
else l[i] = -1;
s.push(i);
}
while (!s.empty()) s.pop();
for (int i = n + 1; i >= 0; i--) {
while (!s.empty() && a[s.top()] > a[i]) s.pop();
if (!s.empty()) r[i] = s.top();
else r[i] = -1;
s.push(i);
}
for (int i = 0; i <= n + 1; i++) {
if (l[i] != -1) g[i].push_back(l[i]);
if (r[i] != -1) g[r[i]].push_back(i);
}
for (int i = 1; i <= n + 1; i++) {
dp[i] = i - 1;
for (int j : g[i]) smin(dp[i], dp[j] + i - j - 1);
}
cout << dp[n + 1] << en;
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
4948 KB |
Output is correct |
| 2 |
Incorrect |
3 ms |
4948 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
4948 KB |
Output is correct |
| 2 |
Incorrect |
3 ms |
4948 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
4948 KB |
Output is correct |
| 2 |
Incorrect |
3 ms |
4948 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
3 ms |
4948 KB |
Output is correct |
| 2 |
Incorrect |
3 ms |
4948 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
