Submission #407589

#	Time	Username	Problem	Language	Result	Execution time	Memory
407589		juggernaut	Circle selection (APIO18_circle_selection)	C++17	12 / 100	802 ms	36492 KiB

circle_selection

#include <bits/stdc++.h>
    using i64 = long long;
    inline i64 sq(int x) { return i64(x) * x; }
    int main(){
        std::ios::sync_with_stdio(false);
        std::cin.tie(nullptr);
        int n;
        std::cin >> n;
        std::vector<int> x(n), y(n), r(n);
        for (int i = 0; i < n; i++) {
            std::cin >> x[i] >> y[i] >> r[i];
        }
        std::vector<int> ans(n, -1);
        std::vector<int> ind(n);
        iota(ind.begin(), ind.end(), 0);
        sort(ind.begin(), ind.end(), [&](int i, int j) {
            if (r[i] == r[j]) return i < j;
            return r[i] > r[j];
        });
        std::set<std::pair<int, int>> sr;
        for (int i = 0; i < n; i++) {
            sr.emplace(x[i] + r[i], i);
            sr.emplace(x[i] - r[i], i);
        }
        for (auto i : ind) {
          if(~ans[i])continue;
            while (sr.size()) {
                auto it = sr.lower_bound({x[i] - r[i], -1});
                if (it == sr.end()) break;
                int j = it->second;
              if(it->first>x[i]+r[i])break;
                sr.erase(it);
              if(~ans[it->second])continue;
              ans[it->second]=i;
            }
        }
        for (auto x : ans) assert(~x), std::cout << x + 1 << ' ';
        std::cout << '\n';
    }

Compilation message (stderr)

circle_selection.cpp: In function 'int main()':
circle_selection.cpp:30:21: warning: unused variable 'j' [-Wunused-variable]
   30 |                 int j = it->second;
      |                     ^

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