Submission #250322

#	Time	Username	Problem	Language	Result	Execution time	Memory
250322		errorgorn	Cake 3 (JOI19_cake3)	C++14	100 / 100	1223 ms	219808 KiB

cake3

//雪花飄飄北風嘯嘯
//天地一片蒼茫

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
#define ll long long
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define fi first
#define se second
#define endl '\n'
#define debug(x) cout << #x << " is " << x << endl;

#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()

ll MAX(ll a){return a;}
ll MIN(ll a){return a;}
template<typename... Args>
ll MAX(ll a,Args... args){return max(a,MAX(args...));}
template<typename... Args>
ll MIN(ll a,Args... args){return min(a,MIN(args...));}

#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());

int n,k;
ii arr[200005];
vector<int> uni;
map<int,int> vmap;

struct wavelet{
    vector<int> index; ///indexes inside this segment
    vector<int> val; ///values inside this segment (sorted)
	vector<ll> pref;
    vector<int> l_child;
    vector<int> r_child;
    int _min,_max;
    wavelet *l, *r;
    wavelet(){}

    void init(){
        _min=val.front();
        _max=val.back();
		
		pref.push_back(0);
		rep(x,0,sz(val)) pref.push_back(pref.back()+uni[arr[index[x]].fi]);
		
        if (_min==_max) return; ///dont need to propogate more
        l=new wavelet();
        r=new wavelet();
        int pivot=max(val[val.size()>>1],_min+1);
        l_child.push_back(-1);
        r_child.push_back(-1);
		for (int x=0;x<val.size();x++){
            ///we handle val and index seperately
            if (val[x]<pivot) l->val.push_back(val[x]);
            else r->val.push_back(val[x]);

            if (arr[index[x]].fi<pivot){ //arr stores values of stuff
                l->index.push_back(index[x]);
                l_child.push_back(l_child.back()+1);
                r_child.push_back(r_child.back());
            }
            else {
                r->index.push_back(index[x]);
                l_child.push_back(l_child.back());
                r_child.push_back(r_child.back()+1);
            }
        }
		
		l->init();
        r->init();
    }

    ll query(int i,int j,ll k){
		if (_min==_max) return k*uni[_min];
		
		int len=r_child[j+1]-r_child[i];
		
		if (len<=k) return r->pref[r_child[j+1]+1]-r->pref[r_child[i]+1]+l->query(l_child[i]+1,l_child[j+1],k-len);
		else return r->query(r_child[i]+1,r_child[j+1],k);
    }
}*root=new wavelet();

ll ans=-1e18;

void dp(int l,int r,int optl,int optr){
	if (l>r) return;
	
	int m=l+r>>1;
	int optm=-1;
	
	ll best=-1e18;
	
	rep(x,optl,optr+1) if (x-m+1>=k){
		ll val=2*(arr[m].se-arr[x].se)+uni[arr[m].fi]+uni[arr[x].fi]+root->query(m+1,x-1,k-2);
		
		//cout<<m<<" "<<x<<" "<<val<<endl;
		
		if (val>best){
			best=val;
			optm=x;
		}
	}
	
	ans=max(ans,best);
	dp(l,m-1,optl,optm),dp(m+1,r,optm,optr);
}

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	cin>>n>>k;
	rep(x,0,n){
		cin>>arr[x].fi>>arr[x].se;
		uni.push_back(arr[x].fi);
	}
	
	sort(arr,arr+n,[](ii i,ii j){
		return i.se<j.se;
	});
	
	sort(all(uni));
	uni.erase(unique(all(uni)),uni.end());
	
	rep(x,0,sz(uni)){
		vmap[uni[x]]=x;
	}
	
	rep(x,0,n){
		arr[x].fi=vmap[arr[x].fi];
		
		root->index.push_back(x);
		root->val.push_back(arr[x].fi);
	}
	
	sort(all(root->val));
	root->init();
	
	//rep(x,0,n) cout<<uni[arr[x].fi]<<" "; cout<<endl;
	
	dp(0,n-k,0,n-1);
	
	cout<<ans<<endl;
}

Compilation message (stderr)

cake3.cpp: In member function 'void wavelet::init()':
cake3.cpp:62:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int x=0;x<val.size();x++){
                ~^~~~~~~~~~~
cake3.cpp: In function 'void dp(int, int, int, int)':
cake3.cpp:98:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int m=l+r>>1;
        ~^~

• Subtask 1: 5 / 5
• Subtask 2: 19 / 19
• Subtask 3: 76 / 76