Submission #204931

#TimeUsernameProblemLanguageResultExecution timeMemory
204931oolimryCircle selection (APIO18_circle_selection)C++14
12 / 100
3082 ms285472 KiB
#include <bits/stdc++.h>

using namespace std;
typedef pair<long long, long long> ii;

int n; 

struct Circle{
  long long x, y, r, id;
} sorted[300005], arr[300005];;

bool intersect(Circle a, Circle b){
  return (a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y) <= (a.r + b.r) * (a.r + b.r);
}

long long ans[300005];

struct pair_hash{
  std::size_t operator () (ii const &pair) const{
    return pair.first ^ pair.second;
  }
};

unordered_map<ii, vector<int>, pair_hash> GRID;
long long gridSize = 1LL << 61LL;

void buildGrid(long long newGridSize){
  gridSize = newGridSize;
  GRID.clear();

  for(int i = 0;i < n;i++){
    if(ans[i] == -1){
      long long xSquare = arr[i].x / gridSize;
      long long ySquare = arr[i].y / gridSize;
      GRID[ii(xSquare,ySquare)].push_back(i);
    }
  }
}

bool comp(Circle a, Circle b){
  if(a.r == b.r) return a.id < b.id;
  else return a.r > b.r;
}

int main(){
  ios_base::sync_with_stdio(false);
  cin.tie(0);

  cin >> n;
  fill(ans, ans + n, -1);

  for(int i = 0;i < n;i++){
    long long x, y, r; cin >> x >> y >> r;
    x += (1LL << 31LL); y += (1LL << 31LL);
    arr[i] = {x, y, r, i};
    sorted[i] = {x, y, r, i};
  }

  sort(sorted,sorted+n,comp);

  for(int i = 0;i < n;i++){
    Circle C = sorted[i];

    if(ans[C.id] != -1) continue;
    //ans[C.id] = C.id;

    if(gridSize > 2 * C.r){
      buildGrid(C.r);
    }

    long long xSquare = C.x / gridSize;
    long long ySquare = C.y / gridSize;

    for(long long x = xSquare - 2;x <= xSquare + 2;x++){
      for(long long y = ySquare - 2;y < ySquare + 2;y++){
        vector<int> &points = GRID[ii(x,y)];

        for(int p = 0;p < (int) points.size();p++){
          if(intersect(arr[points[p]],C)){
            ans[points[p]] = C.id;

            points[p] = points.back();
            points.pop_back();
            p--;
          }
        }
      }
    }
  }

  for(int i = 0;i < n;i++) cout << ans[i] + 1 << " ";
}
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