제출 #798175

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
798175		andecaandeci	Rabbit Carrot (LMIO19_triusis)	C++17	100 / 100	23 ms	4896 KiB

triusis

 #include<bits/stdc++.h>
#define fi first
#define se second
#define pq priority_queue
#define mp make_pair
#define str string
#define ll long long
#define ii pair<int, int>
#define pb push_back
#define MOD 1000000007

using namespace std;

// Feeling stuck? Scroll down for important points! Don't do nothing!
// Don't forget to see constraints, and to comment the cin t if unneccessary

// portal: lat soal osn 29 juli ben pres: rabbit carrot
// solution idea: create b[i] = m*i - a[i] then find LIS, ans = n - LIS 
// why: we are finding the ones we don't need to change rather than the ones we need to change.
// sample proof: 100 100 300 change middle lis is 100 300

const int N=2e5+5;
int a[N], b[N], n, m;
void solve() {
  cin >> n >> m;
  for (int i=1; i<=n; i++) cin >> a[i];
  for (int i=1; i<=n; i++) b[i] = (m*i) - a[i];
  vector<int> lis;
  for (int i=1; i<=n; i++) {
    if (b[i] < 0) continue;
    if (lis.empty() || lis.back() <= b[i]) lis.pb(b[i]);
    else {
      int l=0, r=lis.size()-1, res=0;
      while (l<=r) {
        int mid=(l+r)/2;
        if (lis[mid] > b[i]) {
          res=mid;
          r=mid-1;
        }
        else l=mid+1;
      }
      lis[res] = b[i];
    }
  }
  cout << n-lis.size() << "\n";
     
}

int main() {
  // your code goes here
  ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
  int t=1;
  // comment below if no test cases!
//  cout << "INPUT T: " << endl;
//  cin>>t;
  while(t--)
  {
      solve();
  }

  return 0;
}

// Remember to do easier subtasks for ALL problms
// in IO when stuck for too long
// Don't stare at the screen, nothing will come into your mind
// Actively try to view problem from different perspectives
// and or implement them quick if idea is doable

• Subtask 1: 14 / 14
• Subtask 2: 21 / 21
• Subtask 3: 28 / 28
• Subtask 4: 37 / 37