Submission #571596

#	Time	Username	Problem	Language	Result	Execution time	Memory
571596		Cross_Ratio	Circle selection (APIO18_circle_selection)	C++14	0 / 100	694 ms	56736 KiB

circle_selection

#include <bits/stdc++.h>
#define int long long
using namespace std;
typedef pair<int,int> P;
int X[300005];
int Y[300005];
int R[300005];
int ans[300005];
bool used[300005];
signed main() {
    cin.sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int N;
    cin >> N;
    int i, j;
    for(i=0;i<N;i++) cin >> X[i] >> Y[i] >> R[i];
    priority_queue<P> PQ;
    set<P> S1, S2;
    for(i=0;i<N;i++) {
        S1.insert(P(X[i]+R[i],i));
        S2.insert(P(X[i]-R[i],i));
        PQ.push(P(R[i],-i));
        ans[i] = -1;
    }
    while(true) {
        int id = -1;
        while(!PQ.empty()) {
            P k = PQ.top();
            PQ.pop();
            if(!used[-k.second]) {
                id = -k.second;
                break;
            }
        }
        if(id==-1) break;
        auto it1 = S1.lower_bound(P(X[id]-R[id],0));
        while(it1 != S1.end()&&it1->second <= X[id] + R[id]) {
            ans[it1->second] = (ans[it1->second]==-1?id : ans[it1->second]);
            used[it1->second] = true;
            auto it2 = it1;
            it1++;
            S1.erase(it2);
        }
        it1 = S2.lower_bound(P(X[id]-R[id],0));
        while(it1 != S2.end()&&it1->second <= X[id] + R[id]) {
            ans[it1->second] = (ans[it1->second]==-1?id : ans[it1->second]);
            used[it1->second] = true;
            auto it2 = it1;
            it1++;
            S2.erase(it2);
        }
    }
    for(i=0;i<N;i++) cout << ans[i]+1 << ' ';
}

Compilation message (stderr)

circle_selection.cpp: In function 'int main()':
circle_selection.cpp:16:12: warning: unused variable 'j' [-Wunused-variable]
   16 |     int i, j;
      |            ^

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