Submission #943294

#	Time	Username	Problem	Language	Result	Execution time	Memory
943294		shoryu386	Road Construction (JOI21_road_construction)	C++17	5 / 100	10130 ms	815140 KiB

road_construction

#include <bits/stdc++.h>
using namespace std;

#define int long long

struct node{
	int s, e, m;
	int v;
	node *l = nullptr, *r = nullptr;
	
	node(int _s, int _e){
		s = _s, e = _e, m = s + (e-s)/2;
		v = 0;
	}
	
	void del(){
		if (l != nullptr) l->del();
		if (r != nullptr) r->del();
		
		delete this;
	}
	
	void make_left(){
		if (s != e && l == nullptr) l = new node(s, m);
	}
	void make_right(){
		if (s != e && r == nullptr) r = new node(m+1, e);
	}
	
	int query(int qs, int qe){
		if (qs == s && e == qe) return v;
		
		
		
		if (qe <= m) {make_left(); return l->query(qs, qe);}
		else if (qs > m) {make_right(); return r->query(qs, qe);}
		else {make_left(); make_right(); return l->query(qs, m) + r->query(m+1, qe);}
	}
	
	void update(int x, int k){
		if (s == e) {v += k; return;}
		
		if (x <= m) {make_left(); l->update(x, k);}
		else {make_right(); r->update(x, k);}
		
		v = 0;
		if (l != nullptr) v += l->v;
		if (r != nullptr) v += r->v;
	}
};

main(){
	int n, k; cin >> n >> k;
	
	pair<int, int> arr[n];
	for (int x = 0; x < n; x++){
		cin >> arr[x].first >> arr[x].second;
	}
	
	//consider manhattan distance trick?
	for (int x = 0; x < n; x++){
		arr[x] = {arr[x].first + arr[x].second, arr[x].first - arr[x].second};
	}
	sort(arr, arr+n); //sorted by x-coord
	
	//now chebyshev distance, dist = max of difference
	
	//I want to bsearch, but bsearch only gives location of boundary; I need sum of boundary
	
	
	int l = 0, r = 4'000'000'000LL, ans = 4'000'000'000LL;
	while (l <= r){
		int m = (l+r)/2;
		int cnt = 0;
		
		node *seg = new node(-8'000'000'007LL, 8'000'000'007LL);
		priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
		
		for (int x = 0; x < n; x++){
			while (!pq.empty() && pq.top().first <= arr[x].first){
				seg->update(arr[ pq.top().second ].second, -1);
				pq.pop();
			}
			cnt += seg->query(arr[x].second - m, arr[x].second + m);
			
			seg->update(arr[x].second, 1);
			pq.push({arr[x].first+m+1, x});
		}
		
		if (cnt < k){
			l = m+1;
		}
		else{
			ans = m;
			r = m-1;
		}
		
		seg->del();
	}
	
	
	vector<int> clown;
	for (int x = 0; x < n; x++){
		for (int y = x+1; y <= min(x+k+2, n-1); y++){
			clown.push_back( max( abs(arr[x].first - arr[y].first), abs(arr[x].second - arr[y].second) ) );
		}
	}
	
	sort(clown.begin(), clown.end());
	for (int x = 0; x < k; x++) cout << clown[x] << '\n';
	
	assert(clown[k-1] == ans);
}

Compilation message (stderr)

road_construction.cpp:52:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   52 | main(){
      | ^~~~

• Subtask 1: 5 / 5
• Subtask 2: 0 / 6
• Subtask 3: 0 / 7
• Subtask 4: 0 / 20
• Subtask 5: 0 / 27
• Subtask 6: 0 / 35