Submission #1292634

#	Time	Username	Problem	Language	Result	Execution time	Memory
1292634		Hamed_Ghaffari	Circle selection (APIO18_circle_selection)	C++20	0 / 100	3095 ms	25016 KiB

circle_selection

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

using ll = long long;
using pii = pair<int, int>;

#define X first
#define Y second
#define all(x) x.begin(), x.end()
#define SZ(x) int(x.size())

const int MXN = 3e5+5;
const int LOG = 31;

struct circle {
    int x, y, r, id;
};

bool isect(circle &c1, circle &c2) {
    ll x = c1.x - c2.x;
    ll y = c1.y - c2.y;
    return 1ll*(c1.r+c2.r)*(c1.r+c2.r) >= x*x + y*y;
}

struct {
    int t;
    vector<pii> cmp;
    vector<vector<circle>> vec;
    void add_(circle c) {
        cmp.push_back(pii(c.x/t, c.y/t));
    }
    void build() {
        sort(all(cmp));
        cmp.resize(unique(all(cmp))-cmp.begin());
        vec.resize(SZ(cmp));
    }
    int GI(pii x) { return lower_bound(all(cmp), x)-cmp.begin(); }
    void add(circle c) {
        vec[GI(pii(c.x/t, c.y/t))].push_back(c);
    }
    int find(circle &c) {
        for(auto x : vec)
            for(auto c2 : x)
                if(isect(c, c2))
                    return c2.id;
        // for(int i=c.x/t-2; i<=c.x/t+2; i++) {
        //     int pos = GI(pii(i, c.y/t-2));
        //     while(pos<SZ(cmp) && cmp[pos].X==i && cmp[pos].Y<=c.y/t+2) {
        //         for(auto &c2 : vec[pos])
        //             if(isect(c, c2))
        //                 return c2.id;
        //         pos++;
        //     }
        // }
        return -1;
    }
} ds[LOG];

int get_id(int r) {
    return 0;
    int l = __lg(r);
    if((1<<l)<r) l++;
    return l;
}

void init() {
    for(int i=0; i<LOG; i++) ds[i].t = 1<<i;
}

void add_(circle c) {
    ds[get_id(c.r)].add_(c);
}

void build() {
    for(int i=0; i<LOG; i++) ds[i].build();
}

void add(circle c) {
    ds[get_id(c.r)].add(c);
}

int find(circle c) {
    for(int i=get_id(c.r); i<LOG; i++) {
        int tmp = ds[i].find(c);
        if(tmp!=-1) return tmp;
    }
    return -1;
}

int n, ans[MXN];
circle c[MXN];

int32_t main() {
    cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0);
    cin >> n;
    init();
    for(int i=0; i<n; i++) {
        cin >> c[i].x >> c[i].y >> c[i].r;
        c[i].x += 1e9;
        c[i].id = i;
        add_(c[i]);
    }
    build();
    sort(c, c+n, [&](circle &c1, circle &c2) {
        return c1.r > c2.r || (c1.r == c2.r && c1.id < c2.id);
    });
    for(int i=0; i<n; i++) {
        // int tmp = find(c[i]);
        int tmp = -1;
        for(int j=0; j<i; j++)
            if(ans[c[j].id] == c[j].id && isect(c[j], c[i]))
                tmp = c[j].id;
        if(tmp==-1) {
            ans[c[i].id] = c[i].id;
            add(c[i]);
        }
        else ans[c[i].id] = tmp;
    }
    for(int i=0; i<n; i++) cout << ans[i]+1 << ' ';
    cout << '\n';
    return 0;
}

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