Submission #1216618

#	Time	Username	Problem	Language	Result	Execution time	Memory
1216618		kokoxuya	The short shank; Redemption (BOI21_prison)	C++20	15 / 100	2095 ms	68344 KiB

prison

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pb push_back
#define mp make_pair
#define pii pair<int,int>
#define ss second
#define ff first
#define piii pair<int,pii>
#define debu(x) (cerr << #x  << " = "<< x << "\n")
#define debu2(x,y) (cerr << #x  << " = "<< x << " " << #y << " = " << y << "\n")
#define debu3(x,y,z) (cerr << #x  << " = "<< x << " " << #y << " = " << y << " " << #z << " = " << z<< "\n")
#define bitout(x,y) {\
	cerr << #x << " : ";\
	for (int justforbits = y; justforbits >=0; justforbits--)cout << (((1 << justforbits) & x)>=1);\
	cout << "\n";\
}
#define rangeout(j,rangestart,rangeend) {\
	cerr << "outputting" << #j<< ":\n";\
	for (int forrang = rangestart; forrang <= rangeend; forrang++)cerr << j[forrang] << " ";\
	cerr<<"\n";\
}
#define c1 {cerr << "Checkpoint 1! \n\n";cerr.flush();}
#define c2 {cerr << "Checkpoint 2! \n\n";cerr.flush();}
#define c3 {cerr << "Checkpoint 3! \n\n";cerr.flush();}
#define c4 {cerr << "Checkpoint 4! \n\n";cerr.flush();}


signed main()
{
    int t1,t2,t3,t4;
    mt19937_64 rnd(chrono::high_resolution_clock::now().time_since_epoch().count());
    //ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	
	int n,d,t;cin>>n>>d>>t;	
	
	priority_queue<piii,vector<piii>,greater<piii>>pq;
	for(int a=1;a<=n;a++)
	{
		cin>>t1;
		if(t1<=t)pq.push(mp(a,mp(a+(t-t1),a)));
	}
	
	set<int>curr;
	priority_queue<pii,vector<pii>,greater<pii>>ends;
	vector<int>foreach(n+1,0);
	int tots=0;
	
	for(int a=1;a<=n;a++)
	{
		while(!pq.empty()&&pq.top().ff<=a)
		{
			curr.insert(pq.top().ss.ss);
			ends.push(pq.top().ss);
			pq.pop();
		}
		while(!ends.empty()&&ends.top().ff<a)
		{
			curr.erase(ends.top().ss);
			ends.pop();
		}
		
		if(!curr.empty())
		{
			tots++;
			foreach[a]=(*prev(curr.end()));
		}
	}	
	
	
	//rangeout(foreach,1,n);
	//new
	vector<vector<int>>dp(n+5,vector<int>(d+1,tots));
	vector<priority_queue<int>>starteach(n+5);	
	
	//sets -> a collection of the things I have
	for(int a=n;a>=1;a--)//up to (inclusive)
	{
		if(foreach[a]!=0)for(int b=n+4;b>=a;b--){starteach[b].push(foreach[a]);}
		for(int b=1;b<=d;b++)//number of mattresses
		{
			for(int c=((n+1)-(b-1));c>=a+1;c--)//prior number -> at least must have b-1 people
			{
				//debu3(a,b,c);
				while(!starteach[c-1].empty()&&starteach[c-1].top()>=a)
				{
					starteach[c-1].pop();
				}
				dp[a][b]=min(dp[a][b],dp[c][b-1]-(int)starteach[c-1].size());
				//debu(dp[a][b]);
			}
		}
	}
		
	int ans=n;
	for(int a=1;a<=n;a++)
	{
		ans=min(dp[a][d],ans);
	}
	cout<<ans;
	
	//place it to my left
}

//dp[x][y]=max(dp[i][y-1]+ifputthere); for each i
//-> each if put there -= those who are after i

//between last cut and current cut with numbers smaller than me
//^^store each one ending at x -> then when something pops up that is more then add it

//current cut has to be made at where I am right now
//dp[current at][cutnumber]=for each i at which the previous cut was made:
//dp[i][cutnumber-1]+no of things between i and current at whose endings are > current at
//(including current at into my current segment)

//a set ending at each person ->
//-> number above me is lower_bound it

//speed up?? -> do we need to find all i? (i fhv time try)
//only ever gets increasingly bigger -> just pop out while is bigger than 

• Subtask 1: 15 / 15
• Subtask 2: 0 / 10
• Subtask 3: 0 / 20
• Subtask 4: 0 / 10
• Subtask 5: 0 / 25
• Subtask 6: 0 / 20