Submission #520893

#	Time	Username	Problem	Language	Result	Execution time	Memory
520893		errorgorn	3D Histogram (COCI20_histogram)	C++17	110 / 110	342 ms	92672 KiB

histogram

// Super Idol的笑容
//    都没你的甜
//  八月正午的阳光
//    都没你耀眼
//  热爱105°C的你
// 滴滴清纯的蒸馏水

#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 int long long
#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 << ": " << x << endl

#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define lb lower_bound
#define ub upper_bound

#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()

#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
//change less to less_equal for non distinct pbds, but erase will bug

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

struct node{
	int s,e,m;
	int val=0;
	node *l,*r;
	
	node (int _s,int _e){
		s=_s,e=_e,m=s+e>>1;
		
		if (s!=e){
			l=new node(s,m);
			r=new node(m+1,e);
		}
	}
	
	void update(int i,int k){
		if (s==e){
			val=k;
		}
		else{
			if (i<=m) l->update(i,k);
			else r->update(i,k);
			
			val=min(l->val,r->val);
		}
	}
	
	int query(int i,int j){
		if (s==i && e==j) return val;
		else{
			if (j<=m) return l->query(i,j);
			else if (m<i) return r->query(i,j);
			else return min(l->query(i,m),r->query(m+1,j));
		}
	}
} *root2=new node(0,200005);

int n;
int arr[200005];
int brr[200005];

struct range{
	int l,r,v;
};

vector<range> ar,br;

struct line{
	int m=0,c=-1e12;
	int get(int x){
		return m*x+c;
	}
};
struct lichao{
	int s,e,m;
	line val;
	lichao *l,*r;
	
	lichao (int _s,int _e){
		s=_s,e=_e,m=s+e>>1;
		
		if (s!=e){
			l=new lichao(s,m);
			r=new lichao(m+1,e);
		}
	}
	
	void update(line k){
		bool lo=val.get(s)<k.get(s);
		bool mi=val.get(m)<k.get(m);
		bool hi=val.get(e)<k.get(e);
		
		if (mi) swap(val,k);
		if (lo==hi || k.c==-1e18 || s==e) return;
		if (lo!=mi) l->update(k);
		else r->update(k);
	}
	
	void update(int i,int j,line k){
		// if (s==0 && e==200005){
			// rep(x,i,j+1) cout<<k.get(x)<<" "; cout<<endl;
		// }
		if (s==i && e==j) update(k);
		else{
			if (j<=m) l->update(i,j,k);
			else if (m<i) r->update(i,j,k);
			else l->update(i,m,k),r->update(m+1,j,k);
		}
	}
	
	int query(int i){
		if (s==e) return val.get(i);
		else if (i<=m) return max(val.get(i),l->query(i));
		else return max(val.get(i),r->query(i));
	}
} *root;

signed main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin.exceptions(ios::badbit | ios::failbit);
	
	cin>>n;
	rep(x,1,n+1) cin>>arr[x]>>brr[x];
	rep(x,1,n+1) root2->update(x,brr[x]);
	
	ll ans=0;
	rep(zzz,0,2){
		root=new lichao(0,200005);
		reverse(arr+1,arr+n+1);
		reverse(brr+1,brr+n+1);
		ar.clear(),br.clear();
		
		
		vector<int> idx={0};
		rep(x,1,n+2){
			while (arr[idx.back()]>arr[x]){
				int temp=arr[idx.back()];
				idx.pob();
				ar.pub(range({idx.back()+1,x-1,temp}));
				if (zzz) ans=max(ans,temp*(x-idx.back()-1)*root2->query(idx.back()+1,x-1));
			}
			idx.pub(x);
		}
		
		idx={0};
		rep(x,1,n+2){
			while (brr[idx.back()]>brr[x]){
				int temp=brr[idx.back()];
				idx.pob();
				br.pub(range({idx.back()+1,x-1,temp}));
			}
			idx.pub(x);
		}
		
		sort(all(ar),[](range i,range j){
			return i.r<j.r;
		});
		sort(all(br),[](range i,range j){
			return i.r<j.r;
		});
		
		int pos=0;
		
		for (auto [l,r,v]:ar){
			while (pos!=sz(br) && br[pos].r<=r){
				int l=br[pos].l,r=br[pos].r,v=br[pos].v;
				//cout<<"adding: "<<l<<" "<<r<<" "<<v<<endl;
				root->update(l,r,line({-v,(r+1)*v}));
				root->update(0,l-1,line({0,(r-l+1)*v}));
				pos++;
			}
			ans=max(ans,v*root->query(l));
		}
	}
	
	cout<<ans<<endl;
}

Compilation message (stderr)

histogram.cpp: In constructor 'node::node(long long int, long long int)':
histogram.cpp:46:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   46 |   s=_s,e=_e,m=s+e>>1;
      |               ~^~
histogram.cpp: In constructor 'lichao::lichao(long long int, long long int)':
histogram.cpp:98:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   98 |   s=_s,e=_e,m=s+e>>1;
      |               ~^~

• Subtask 1: 20 / 20
• Subtask 2: 90 / 90