#include <bits/stdc++.h>
using namespace std;
using ll = long long;
mt19937 rng(228);
const int N = 1e6 + 1;
int a[N], ans[N];
const int G = (1 << 20);
int t[2 * G];
int get(int ql, int qr) {
int ans = 0;
for (ql += G, qr += G; ql <= qr; ql >>= 1, qr >>= 1) {
if (ql & 1) ans ^= t[ql++];
if (~qr & 1) ans ^= t[qr--];
}
return ans;
}
void upd(int ql, int val) {
for (ql += G, t[ql] ^= val, ql >>= 1; ql; ql >>= 1) t[ql] = t[ql << 1] ^ t[ql << 1 | 1];
}
signed main() {
cin.tie(nullptr)->sync_with_stdio(false);
int n;
cin >> n;
for (int i = 0; i < n; i++) cin >> a[i];
for (int i = 1; i < n; i++) {
if (a[i-1] > a[i]) continue;
if (a[i-1] == a[i] || a[i] == a[i-1] + 1) {
ans[i] = 1;
if (ans[i-1] == 1 && a[i-1] + 1 <= a[i] - 1) {
int t = rng();
upd(a[i-2] + 1, t);
upd(a[i] - 1, t);
}
continue;
}
int good = get(a[i-1], a[i]);
if (good == 0) {
ans[i] = 1;
int t = rng();
upd(a[i-1] + 1, t);
upd(a[i] - 1, t);
if (ans[i-1] == 1) {
t = rng();
upd(a[i-2] + 1, t);
upd(a[i] - 1, t);
}
}
}
cout << n - accumulate(ans, ans + N, 0) << "\n";
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
4440 KB |
Output is correct |
2 |
Incorrect |
2 ms |
4444 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
4440 KB |
Output is correct |
2 |
Incorrect |
2 ms |
4444 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
4440 KB |
Output is correct |
2 |
Incorrect |
2 ms |
4444 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
4440 KB |
Output is correct |
2 |
Incorrect |
2 ms |
4444 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |