Submission #699869

#	Time	Username	Problem	Language	Result	Execution time	Memory
699869		nima_aryan	Global Warming (CEOI18_glo)	C++14	0 / 100	68 ms	4188 KiB

glo

#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "algo/debug.h"
#endif

const int inf = 1e9;

vector<int> lis(vector<int> const& a, bool value = false) {
   int n = (int) a.size();
   vector<int> ret(n);
   vector<int> d(n + 1, inf);
   d[0] = -inf;
   for (int i = 0; i < n; ++i) {
      int j = (int) distance(d.begin(),
                             upper_bound(d.begin(), d.end(), a[i])
                            );
      if (d[j - 1] < a[i] && a[i] < d[j]) {
         ret[i] = j;
         d[j] = a[i];
      }
   }
   if (value) {
      for (int i = 0; i <= n; ++i) {
         if (d[i] < inf) {
            ret[0] = i;
         }
      }
   }
   return ret;
}

int main() {
   ios::sync_with_stdio(false);
   cin.tie(nullptr);
   int n, x;
   cin >> n >> x;
   vector<int> t(n);
   for (int i = 0; i < n; ++i) {
      cin >> t[i];
   }
   int ans = lis(t, true).front();
   for (int i = 0; i < n; ++i) {
      t[i] -= x;
   }
   vector<int> L = lis(t);
   for (int i = 0; i < n; ++i) {
      t[i] += x;
   }
   reverse(t.begin(), t.end());
   vector<int> R = lis(t);
   reverse(R.begin(), R.end());
   for (int i = 0; i < n; ++i) {
      ans = max(ans, L[i] + R[i] - 1);
   }
   cout << ans << '\n';
}

/* stuff you should look for
 * int overflow, array bounds
 * special cases (n=1?)
 * do smth instead of nothing and stay organized
 * WRITE STUFF DOWN
 * DON'T GET STUCK ON ONE APPROACH
 */

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