Submission #1104184

#	Time	Username	Problem	Language	Result	Execution time	Memory
1104184		vjudge1	Global Warming (CEOI18_glo)	C++17	100 / 100	42 ms	4308 KiB

glo

#include <bits/stdc++.h>
using namespace std;

const int N = 2e5 + 3;
int ar[N];

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int n, g; cin >> n >> g;
  for(int i=1; i<=n; ++i) cin >> ar[i];

  int res = 1;
  int dp[n+1];
  dp[0] = 0;
  vector<int> lis;
  for(int i=1; i<=n; ++i) {
    auto t = lower_bound(lis.begin(), lis.end(), ar[i]);
    dp[i] = t - lis.begin() + 1;

    if(t == lis.end()) lis.emplace_back(ar[i]);
    else *t = ar[i];

    //cout << dp[i] << " \n"[i == n]; 
  }

  res = lis.size();
  lis.clear();
  for(int i=n; i>=1; --i) {
    int x = lower_bound(lis.begin(), lis.end(), -ar[i] + 2*g) - lis.begin();

    //cout << "I: " << i << " => ";
    //for(auto x : lis) cout << x << ' ';
    //cout << " | " << x << endl;
    res = max(res, dp[i] + x );

    int y = lower_bound(lis.begin(), lis.end(), -ar[i] + g) - lis.begin();
    if(y == lis.size()) lis.emplace_back(-ar[i] + g);
    else lis[y] = -ar[i] + g;
  }

  cout << res << '\n';
  return 0;
}

Compilation message (stderr)

glo.cpp: In function 'int main()':
glo.cpp:37:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |     if(y == lis.size()) lis.emplace_back(-ar[i] + g);
      |        ~~^~~~~~~~~~~~~

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