Submission #483350

#	Time	Username	Problem	Language	Result	Execution time	Memory
483350		BERNARB01	Global Warming (CEOI18_glo)	C++17	62 / 100	62 ms	6564 KiB

glo

#include <bits/stdc++.h>

using namespace std;

const int N = (int) 3e5 + 9;
const long long inf = (long long) 1e18L;

long long n, x, a[N], dp[N];
pair<long long, long long> suffix_lds_info[N];

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cin >> n >> x;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  long long ans = 1;
  fill(dp, dp + n, inf);
  for (long long i = n - 1; i >= 0; i--) {
    long long j = lower_bound(dp, dp + n, -a[i]) - dp;
    dp[j] = -a[i];
    ans = max(ans, j + 1);
    suffix_lds_info[i] = {ans, -dp[ans - 1]};
  }
  fill(dp, dp + n, inf);
  for (long long i = 0; i < n; i++) {
    a[i] -= x;
    long long j = lower_bound(dp, dp + n, a[i]) - dp;
    dp[j] = a[i];
    if (i + 1 < n) {
      long long ns = suffix_lds_info[i + 1].second;
      long long sl = suffix_lds_info[i + 1].first;
      j = lower_bound(dp, dp + n, ns) - dp;
      j -= 1;
      ans = max(ans, j + 1 + sl);
    }
  }
  cout << ans << '\n';
  return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 13
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 17 / 17
• Subtask 7: 0 / 25