Submission #75660

#	Time	Username	Problem	Language	Result	Execution time	Memory
75660		tmwilliamlin168	Circle selection (APIO18_circle_selection)	C++14	87 / 100	3043 ms	253684 KiB

circle_selection

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

#define ll long long

const int mxN=3e5;
int n, p[mxN], p2[mxN], a[mxN];
ll x[mxN], y[mxN], r[mxN];
unordered_map<int, vector<array<int, 2>>> mp;

void rs(int k) {
	mp.clear();
	for(int i=0; i<n; ++i)
		if(a[p2[i]]==-1)
			mp[x[p2[i]]>>k].push_back({y[p2[i]]>>k, p2[i]});
}

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n;
	for(int i=0; i<n; ++i) {
		cin >> x[i] >> y[i] >> r[i];
		p[i]=p2[i]=i;
	}
	sort(p, p+n, [&](const int &a, const int &b) {
		return r[a]==r[b]?a<b:r[a]>r[b];
	});
	sort(p2, p2+n, [&](const int &a, const int &b) {
		return y[a]<y[b];
	});
	memset(a, -1, 4*n);
	for(int i=-1, k=30; i+1<n; --i, --k) {
		rs(k);
		while(++i<n&&r[p[i]]>=1<<(k-1)) {
			if(a[p[i]]!=-1)
				continue;
			for(ll b=(x[p[i]]>>k)-2; b<=(x[p[i]]>>k)+2; ++b) {
				auto mf=mp.find(b);
				if(mf==mp.end())
					continue;
				vector<array<int, 2>> &v=mf->second;
				for(int j=lower_bound(v.begin(), v.end(), array<int, 2>{(y[p[i]]>>k)-2, 0})-v.begin(); j<v.size()&&v[j][0]<=(y[p[i]]>>k)+2; ++j) {
					ll dx=x[p[i]]-x[v[j][1]], dy=y[p[i]]-y[v[j][1]], rs=r[p[i]]+r[v[j][1]];
					if(dx*dx+dy*dy<=rs*rs&&a[v[j][1]]==-1)
						a[v[j][1]]=p[i];
				}
			}
		}
	}
	for(int i=0; i<n; ++i)
		cout << a[i]+1 << " ";
}

Compilation message (stderr)

circle_selection.cpp: In function 'void rs(int)':
circle_selection.cpp:15:39: warning: narrowing conversion of '(y[p2[i]] >> k)' from 'long long int' to 'int' inside { } [-Wnarrowing]
    mp[x[p2[i]]>>k].push_back({y[p2[i]]>>k, p2[i]});
                               ~~~~~~~~^~~
circle_selection.cpp: In function 'int main()':
circle_selection.cpp:44:73: warning: narrowing conversion of '((y[p[i]] >> k) - 2)' from 'long long int' to 'int' inside { } [-Wnarrowing]
     for(int j=lower_bound(v.begin(), v.end(), array<int, 2>{(y[p[i]]>>k)-2, 0})-v.begin(); j<v.size()&&v[j][0]<=(y[p[i]]>>k)+2; ++j) {
                                                             ~~~~~~~~~~~~^~
circle_selection.cpp:44:93: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int j=lower_bound(v.begin(), v.end(), array<int, 2>{(y[p[i]]>>k)-2, 0})-v.begin(); j<v.size()&&v[j][0]<=(y[p[i]]>>k)+2; ++j) {
                                                                                            ~^~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 12 / 12
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 30 / 30
• Subtask 6: 0 / 13