Submission #107290

#	Time	Username	Problem	Language	Result	Execution time	Memory
107290		leduykhongngu	Circle selection (APIO18_circle_selection)	C++11	49 / 100	3101 ms	62300 KiB

circle_selection

#include <bits/stdc++.h>
#define FOR(i,a,b) for (int i=(a),_b=(b); i<=_b; ++i)
#define FORR(i,a,b) for (int i=(a),_b=(b); i>=_b; --i)
#define REP(i,b) for (int i=0,_b=(b); i<_b; ++i)
#define endl '\n'
#define sz(x) (int) x.size()
#define mod %
#define fillchar(x,y,z) memset(x,z,y)
#define pii pair<int,int>
#define fi first
#define se second
#define mp make_pair
typedef long long int64;
typedef unsigned long long qword;
using namespace std;
const int maxn=3e5+5;
inline int64 sqr(int64 x)
{
    return x*x;
}
struct Circle{
    int64 x,y,r;
    int id;

    bool IsIntersect(const Circle &c)
    {
        return sqr(x-c.x)+sqr(y-c.y)<=sqr(r+c.r);
    }
}cir[maxn];
bool operator <(const Circle &b,const Circle &c)
    {
        return mp(-b.r,b.id)<mp(-c.r,c.id);
    }
vector<vector<pii> > Point;
vector<int> X;
int n;
int ans[maxn];
int main()
{
    #ifdef meomeomeooooo
        freopen("input.txt","r",stdin);
        //freopen(".txt","w",stdout);
    #endif // meomeomeooooo
    iostream::sync_with_stdio(false);
    cin.tie(0);
    cin >> n;
    set<Circle> myset;
    FOR(i,1,n) {
        cin >> cir[i].x >> cir[i].y >> cir[i].r;
        X.push_back(cir[i].x);
        cir[i].id=i;
        myset.insert(cir[i]);
    }
    sort(X.begin(),X.end());
    X.resize(unique(X.begin(),X.end())-X.begin());
    #define GetDec(x) (lower_bound(X.begin(),X.end(),x)-X.begin())
    Point.resize(X.size());
    FOR(i,1,n) {
        int x=GetDec(cir[i].x);
        Point[x].push_back({cir[i].y,cir[i].id});
    }
    REP(i,X.size())
        sort(Point[i].begin(),Point[i].end());
    while (myset.size()) {
        Circle cur=*myset.begin(); myset.erase(cur);
        ans[cur.id]=cur.id;
        int x=cur.x,y=cur.y,r=cur.r;
        int Lx=max(1ll*x-2*r,-1000000000ll);
        int Rx=min(1ll*x+2*r,1000000000ll);
        int Ly=max(1ll*y-2*r,-1000000000ll);
        int Ry=min(1ll*y+2*r,1000000000ll);
        Lx=GetDec(Lx);
        for (int i=Lx; i<X.size()&&X[i]<=Rx; ++i)
            for (int j=lower_bound(Point[i].begin(),Point[i].end(),mp(Ly,0))-Point[i].begin(); j<Point[i].size()&&Point[i][j].fi<=Ry; ++j) {
                int id=Point[i][j].se;
                if (ans[id]==0&&cur.IsIntersect(cir[id])) {
                    ans[id]=cur.id;
                    myset.erase(cir[id]);
                }
            }
    }
    FOR(i,1,n)
        cout << ans[i] << ' ';
    return 0;
}

Compilation message (stderr)

circle_selection.cpp: In function 'int main()':
circle_selection.cpp:73:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i=Lx; i<X.size()&&X[i]<=Rx; ++i)
                        ~^~~~~~~~~
circle_selection.cpp:74:97: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int j=lower_bound(Point[i].begin(),Point[i].end(),mp(Ly,0))-Point[i].begin(); j<Point[i].size()&&Point[i][j].fi<=Ry; ++j) {
                                                                                                ~^~~~~~~~~~~~~~~~

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