Submission #252073

#	Time	Username	Problem	Language	Result	Execution time	Memory
252073		Mlxa	Circle selection (APIO18_circle_selection)	C++14	0 / 100	3091 ms	53588 KiB

circle_selection

#include <bits/stdc++.h>
using ll = long long;
#define int ll
#define x first
#define y second
#define all(x) x.begin(), x.end()
#define mp make_pair
#define mt make_tuple
using namespace std;

const int N = 3e5 + 5;
int n;
int x[N];
int y[N];
int r[N];
int a[N];
int step = 30;
vector<int> desc;

int sq(int t) {
    return t * t;
}
bool cross(int i, int j) {
    return sq(x[i] - x[j]) + sq(y[i] - y[j]) <= sq(r[i] + r[j]);
}

int id(int xi, int yi) {
    return ((xi >> step) << 30) ^ (yi >> step);
}
map<int, vector<int>> table;

void build() {
    table.clear();
    for (int i = 0; i < n; ++i) {
        if (a[i] == -1) {
            table[id(x[i], y[i])].push_back(i);
        }
    }
}

signed main() {
#ifdef LC
    assert(freopen("input.txt", "r", stdin));
#endif // LC
    ios::sync_with_stdio(0);
    cin.tie(0);

    cin >> n;
    for (int i = 0; i < n; ++i) {
        cin >> x[i] >> y[i] >> r[i];
        a[i] = -1;
        desc.push_back(i);
    }
    sort(all(desc), [&](int i, int j) {
         return mp(-r[i], i) < mp(-r[j], j);
    });
    for (int i : desc) {
        if (a[i] != -1) {
            continue;
        }
        assert((1LL << step) >= 2 * r[i]);
        while ((1LL << step) >= 4 * r[i]) {
            --step;
            build();
        }
        int delta = 1LL << step;
        for (int dx = -2 * delta; dx <= +2 * delta; dx += delta) {
            for (int dy = -2 * delta; dy <= +2 * delta; dy += delta) {
                int v = id(x[i] + dx, y[i] + dy);
                if (!table.count(v)) {
                    continue;
                }
                vector<int> tmp;
                for (int j : table[v]) {
                    if (cross(i, j)) {
                        assert(a[j] == -1);
                        a[j] = i;
                    } else {
                        tmp.push_back(j);
                    }
                }
                table[v] = tmp;
            }
        }
    }
    for (int i = 0; i < n; ++i) {
        cout << a[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