Submission #1075389

#	Time	Username	Problem	Language	Result	Execution time	Memory
1075389		HappyCapybara	Circle selection (APIO18_circle_selection)	C++17	19 / 100	550 ms	62640 KiB

circle_selection

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

double eps = pow(10, -9);

double dist(int ax, int ay, int bx, int by){
    return sqrt(pow(ax-bx, 2)+pow(ay-by, 2));
}

int main(){
    int n;
    cin >> n;
    vector<vector<int>> v(n);
    vector<pair<int,int>> ep;
    for (int i=0; i<n; i++){
        int x, y, r;
        cin >> x >> y >> r;
        v[i] = {-r, i, x, y};
    }

    sort(v.begin(), v.end());
    for (int i=0; i<n; i++){
        ep.push_back({v[i][2]+v[i][0], i});
        ep.push_back({v[i][2]-v[i][0], i});
    }
    sort(ep.begin(), ep.end());
    vector<vector<int>> fts(n);
    for (int i=0; i<2*n; i++){
        //cout << ep[i].first << " " << ep[i].second << "\n";
        fts[ep[i].second].push_back(i);
    }

    set<int> todo;
    for (int i=0; i<n; i++) todo.insert(i);
    vector<int> done(n, 0);
    while (!todo.empty()){
        int cur = *todo.begin();
        if (n <= 5000){
            for (int i=0; i<n; i++){
                if (!done[v[i][1]] && dist(v[cur][2], v[cur][3], v[i][2], v[i][3]) < eps+(double) (0-(v[cur][0]+v[i][0]))){
                    done[v[i][1]] = v[cur][1]+1;
                    todo.erase(i);
                }
            }
        }
        else {
            //cout << cur << "\n";
            int l = fts[cur][0], r = fts[cur][1];
            while (l > 0 && ep[l-1].first == ep[l].first) l--;
            while (r < 2*n-1 && ep[r+1].first == ep[r].first) r++;
            //cout << l << " " << r << "\n";
            for (int i=l; i<=r; i++){
                if (!done[ep[i].second]){
                    done[ep[i].second] = v[cur][1]+1;
                    todo.erase(ep[i].second);
                }
            }
        }
    }
    if (n <= 5000) for (int i=0; i<n; i++) cout << done[i] << "\n";
    else {
        vector<int> w(n);
        for (int i=0; i<n; i++) w[v[i][1]] = i;
        for (int i=0; i<n; i++) cout << done[w[i]] << "\n";
    }
}

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