Submission #387440

#	Time	Username	Problem	Language	Result	Execution time	Memory
387440		uacoder123	Group Photo (JOI21_ho_t3)	C++14	64 / 100	5095 ms	67692 KiB

Main

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
#define F first
#define S second
#define FOR(i,a,b) for (auto i = (a); i <= (b); ++i)
#define NFOR(i,a,b) for(auto i = (a); i >= (b); --i)
#define all(x) (x).begin(), (x).end()
#define sz(x) lli(x.size())
#define mp(i,a) make_pair(i,a)
#define pb(a) push_back(a)
#define bit(x,b) (x&(1LL<<b))
typedef int lli;
typedef pair <lli,lli> ii;
typedef pair <ii,lli> iii;
typedef vector <lli> vi;
typedef tree<lli,null_type,less<lli>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
int n;
int h[5001],dp[5001][5001],p[5001],ans[5001];

int main()
{

      ios_base::sync_with_stdio(false);
      cin.tie(NULL);
  cin>>n;
  for(int i=0;i<n;++i)
  {
    cin>>h[i];
    h[i]--;
    p[h[i]]=i;
  }
  for(int i=0;i<n;++i)
  {
    ordered_set s;
    dp[i][i]=0;
    s.insert(p[i]);
    for(int j=i+1;j<n;++j)
    {
      dp[i][j]=dp[i][j-1]+s.order_of_key(p[j]);
      s.insert(p[j]);
    }
  }
  for(int i=0;i<n;++i)
  {
    ordered_set s,e;
    int v1=0,v2;
  int ans1=n*n;

    for(int j=0;j<=i;++j)
      s.insert(p[j]);
    for(int j=i;j>=0;--j)
    {
      v1-=e.order_of_key(p[j]);
      e.insert(p[j]);
      s.erase(p[j]);
      v1+=s.size()-s.order_of_key(p[j]);
      if(j-1==-1)
        v2=0;
      else
        v2=ans[j-1];
      ans1=min(ans1,v1+dp[j][i]+v2);
    }
    ans[i]=ans1;
  }
  cout<<ans[n-1]<<endl;
  return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 32 / 32
• Subtask 4: 20 / 20
• Subtask 5: 0 / 36