Submission #1356861

#TimeUsernameProblemLanguageResultExecution timeMemory
1356861seungchan1eCircle selection (APIO18_circle_selection)C++20
38 / 100
246 ms55316 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) -> pair<vector<int>, vector<vector<Circle>>> {
        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);

    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) tie(pos, table) = rescale(R);

        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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