Submission #755765

#	Time	Username	Problem	Language	Result	Execution time	Memory
755765		Dan4Life	Road Construction (JOI21_road_construction)	C++17	12 / 100	890 ms	9640 KiB

road_construction

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) begin(a),end(a)
const int mxN = (int)2.5e5+10;
int n, K;
vector<int> ans;
vector<array<int,2>> v;

int calc(int i, int j){ return max(abs(v[i][0]-v[j][0]),abs(v[i][1]-v[j][1])); }

bool chk(int d){
	set<pair<int,int>> S; S.clear(); ans.clear();
	for(int i=0, j=0; i < n and sz(ans)<K; i++){
		while(v[i][0]-v[j][0]>d) S.erase({v[j][1],j}), j++;
		auto itr1 = S.lower_bound({v[i][1]-d,-1});
		auto itr2 = S.lower_bound({v[i][1]+d+1,-1});
		while(itr1!=end(S) and sz(ans)<K and itr1->first < v[i][1]+d)
			ans.pb(calc(itr1->second,i)), itr1++;
		S.insert({v[i][1],i});
	}
	return sz(ans)>=K;
}

int32_t main(){
	ios_base::sync_with_stdio(false); cin.tie(0);
	cin >> n >> K; int x, y;
	for(int i = 0; i < n; i++)
		cin >> x >> y, v.pb({x+y,x-y});
	sort(all(v));
	int l = 0, r = (int)4e9;
	while(l<r){
		int mid = (l+r)>>1;
		if(chk(mid)) r=mid;
		else l=mid+1;
	}
	chk(l); sort(all(ans)); while(sz(ans)<K) ans.pb(l);
	for(auto u : ans) cout << u << "\n";
}

Compilation message (stderr)

road_construction.cpp: In function 'bool chk(long long int)':
road_construction.cpp:19:8: warning: variable 'itr2' set but not used [-Wunused-but-set-variable]
   19 |   auto itr2 = S.lower_bound({v[i][1]+d+1,-1});
      |        ^~~~

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