Submission #827549

#	Time	Username	Problem	Language	Result	Execution time	Memory
827549		mgl_diamond	Global Warming (CEOI18_glo)	C++17	0 / 100	45 ms	4588 KiB

glo

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ii = pair<int, int>;
 
#define foru(i, l, r) for(int i=(l); i<=(r); ++i)
#define ford(i, l, r) for(int i=(l); i>=(r); --i)
#define fore(x, v) for(auto &x : v)
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
#define fi first
#define se second
#define file "input"
 
void setIO(string name="") {
  ios::sync_with_stdio(0);
  cin.tie(0); cout.tie(0);
  if (fopen(file".in", "r")) {
    freopen(file".in", "r", stdin);
    freopen(file".out", "w", stdout);
  }
}

const int N = 2e5+5;
int n, x, a[N], dp[2][N];

int main() {
  setIO();
  cin >> n >> x;
  foru(i, 1, n) cin >> a[i];
  a[n+1] = (int)1e9+1;

  foru(r, 0, 1) {
    vector<int> lis;
    foru(i, 1, n) {
      int it = lower_bound(all(lis), a[i]) - lis.begin();
      if (r) dp[r][i] = it+1;
      if (it == lis.size()) lis.push_back(a[i]);
      else lis[it] = a[i];
      if (!r) dp[r][i] = lower_bound(all(lis), a[i+1]+x) - lis.begin();
    }
    reverse(a+1, a+n+1);
  }

  int ans = 0;
  foru(i, 1, n) ans = max(ans, dp[0][i] + dp[1][n-i]);
  cout << ans;
}

Compilation message (stderr)

glo.cpp: In function 'int main()':
glo.cpp:38:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |       if (it == lis.size()) lis.push_back(a[i]);
      |           ~~~^~~~~~~~~~~~~
glo.cpp: In function 'void setIO(std::string)':
glo.cpp:19:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |     freopen(file".in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
glo.cpp:20:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |     freopen(file".out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• 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