Submission #1356863

#TimeUsernameProblemLanguageResultExecution timeMemory
1356863seungchan1eCircle selection (APIO18_circle_selection)C++20
87 / 100
3065 ms605952 KiB
#include <algorithm>
#include <bits/stdc++.h>

using namespace std;
using ll = long long;

const int MAXN = 303030;

struct Circle {
    int x, y, r, id;
    bool doesIntersect(const Circle& rhs) const {
        ll dx = x - rhs.x;
        ll dy = y - rhs.y;
        ll pr = r + rhs.r;
        return dx * dx + dy * dy <= pr * pr;
    }
};

int n, a[MAXN];
Circle cx[MAXN];

int main()
{
    ios_base::sync_with_stdio(false); cin.tie(NULL);

    cin >> n;
    for(int i = 1; i <= n; i++) {
        cin >> cx[i].x >> cx[i].y >> cx[i].r; cx[i].id = i;
    }

    // vector<Circle> xorder;
    // for(int i = 1; i <= n; i++) xorder.push_back(cx[i]);
    // sort(xorder.begin(), xorder.end(), [](const Circle& a, const Circle& b) { return a.x < b.x; });

    auto rescale = [&](int R) -> map<pair<int, int>, vector<Circle>> {
        map<pair<int, int>, vector<Circle>> res;
        for(int i = 1; i <= n; i++) {
            if(a[i]) continue;
            int r = cx[i].x / R;
            int c = cx[i].y / R;
            res[{r, c}].push_back(cx[i]);
        }
        return res;
        // vector<Circle> tmp;
        // for(auto c : xorder) if(a[c.id] == 0) tmp.push_back(c);
        // xorder = tmp;
        // vector<int> pos;
        // vector<vector<Circle>> res;
        // for(int i = 0; i < xorder.size();) {
        //     int j = i;
        //     vector<Circle> block;
        //     while(j < xorder.size() && xorder[j].x - xorder[i].x < R) {
        //         block.push_back(xorder[j]);
        //         j++;
        //     }
        //     sort(block.begin(), block.end(), [](const Circle& a, const Circle& b){
        //         return a.y < b.y;
        //     });
        //     pos.push_back(xorder[i].x);
        //     res.push_back(block);
        //     i = j;
        // }
        // return {pos, res};
    };

    int R = 1e9;

    vector<int> v(n);
    iota(v.begin(), v.end(), 1);
    sort(v.begin(), v.end(), [](int i, int j) { return tuple(-cx[i].r, i) < tuple(-cx[j].r, j); });

    // auto [pos, table] = rescale(R);
    auto table = rescale(R);

    for(auto i : v) {
        if(a[i]) continue;
        a[i] = i;

        int oldR = R;
        while(R/2 >= cx[i].r) R /= 2;
        if(oldR != R) table = rescale(R);

        int r = cx[i].x / R;
        int c = cx[i].y / R;
        for(int dr = -2; dr <= 2; dr++) {
            for(int dc = -2; dc <= 2; dc++) {
                for(auto c : table[{r+dr, c+dc}]) {
                    if(a[c.id]) continue;
                    if(cx[i].doesIntersect(c)) a[c.id] = i;
                }
            }
        }

        // int sx = upper_bound(pos.begin(), pos.end(), cx[i].x-2*cx[i].r) - pos.begin() - 1;
        // sx = max(sx, 0);
        // for(int j = sx; j < pos.size(); j++) {
        //     if(pos[j] > cx[i].x+2*cx[i].r) break;

        //     auto& t = table[j];
        //     int sy = upper_bound(t.begin(), t.end(), cx[i].y-2*cx[i].r, [](int x, const Circle& c){
        //         return x < c.y;
        //     }) - t.begin() - 1;
        //     sy = max(sy, 0);

        //     for(int k = sy; k < t.size(); k++) {
        //         auto c = t[k];
        //         if(c.y > cx[i].y+2*cx[i].r) break;
        //         if(a[c.id] == 0 && cx[i].doesIntersect(c)) {
        //             a[c.id] = i;
        //         }
        //     }
        // }
    }

    for(int i = 1; i <= n; i++) cout << a[i] << " ";
}
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