Submission #99823

#	Time	Username	Problem	Language	Result	Execution time	Memory
99823		TadijaSebez	Circle selection (APIO18_circle_selection)	C++11	49 / 100	3044 ms	140392 KiB

circle_selection

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define mp make_pair
#define pb push_back
struct circle{ ll x,y,r;int id;circle(){}circle(ll a, ll b, ll c):x(a),y(b),r(c){}};
ll sq(ll x){ return x*x;}
bool sec(circle a, circle b){ return sq(a.x-b.x)+sq(a.y-b.y)<=sq(a.r+b.r);}
const int N=300050;
const ll mul=2e9+7;
circle a[N];
int ans[N];
unordered_map<ll,int> id;
vector<circle> all[N];
int main()
{
	int n,i;
	scanf("%i",&n);
	for(i=1;i<=n;i++) scanf("%lld %lld %lld",&a[i].x,&a[i].y,&a[i].r),a[i].id=i;
	sort(a+1,a+1+n,[](circle a, circle b){ return a.r>b.r || a.r==b.r && a.id<b.id;});
	for(int j=30;j>=0;j--)
	{
		int po=1<<j;
		id.clear();
		int cnt=0;
		for(i=1;i<=n;i++) if(!ans[a[i].id])
		{
			pair<int,int> pa=mp(floor((double)a[i].x/po),floor((double)a[i].y/po));
			ll p=pa.first*mul+pa.second;
			if(!id[p]) id[p]=++cnt,all[cnt].clear();
			all[id[p]].pb(a[i]);
		}
		for(i=1;i<=n;i++) if(!ans[a[i].id] && a[i].r>=(1<<j-1))
		{
			int x=floor((double)a[i].x/po);
			int y=floor((double)a[i].y/po);
			for(int l=-2;l<=2;l++) for(int r=-2;r<=2;r++)
			{
				ll p=(x+l)*mul+y+r;
				if(!id.count(p)) continue;
				int idx=id[p];
				vector<circle> v=all[idx],e;
				for(circle c:v)
				{
					if(sec(c,a[i])) ans[c.id]=a[i].id;
					else e.pb(c);
				}
				all[idx]=e;
			}
		}
	}
	for(i=1;i<=n;i++) printf("%i%c",ans[i],i==n?'\n':' ');
	return 0;
}

Compilation message (stderr)

circle_selection.cpp: In lambda function:
circle_selection.cpp:20:68: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  sort(a+1,a+1+n,[](circle a, circle b){ return a.r>b.r || a.r==b.r && a.id<b.id;});
                                                           ~~~~~~~~~^~~~~~~~~~~~
circle_selection.cpp: In function 'int main()':
circle_selection.cpp:33:54: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   for(i=1;i<=n;i++) if(!ans[a[i].id] && a[i].r>=(1<<j-1))
                                                     ~^~
circle_selection.cpp:18:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%i",&n);
  ~~~~~^~~~~~~~~
circle_selection.cpp:19:67: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(i=1;i<=n;i++) scanf("%lld %lld %lld",&a[i].x,&a[i].y,&a[i].r),a[i].id=i;
                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~

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