Submission #658759

#	Time	Username	Problem	Language	Result	Execution time	Memory
658759		600Mihnea	Circle selection (APIO18_circle_selection)	C++17	Compilation error	0 ms	0 KiB

circle_selection

bool home = 1;

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N = (int) 3e5 + 7;
const int INF = (int) 1e9 + 7;
int n;

struct Circle {
  int x;
  int y;
  int r;
};

bool doIntersect(Circle a, Circle b) {
  /// dist <= a.r + b.r
  /// dist ^  2 <= (a.r + b.r) ^ 2
  return 1LL * (a.x - b.x) * (a.x - b.x) + 1LL * (a.y - b.y) * (a.y - b.y) <= 1LL * (a.r + b.r) * (a.r + b.r);
}


Circle circles[N];
int ret[N];

map<pair<int, int>, vector<int>> guysAtPosition;


bool cmp(int i, int j) {
  if (circles[i].r == circles[j].r) {
    return i < j;
  } else {
    return circles[i].r > circles[j].r;
  }
}
set<int, decltype(cmp)*> s(cmp);

int r_divide_glob;

void place(int r_divide, set<int, decltype(cmp)*>& s) {
  r_divide_glob = r_divide;
  guysAtPosition.clear();
  for (auto &i : s) {
    guysAtPosition[{circles[i].x / r_divide, circles[i].y / r_divide}].push_back(i);
  }
}

void elim(int i, set<int, decltype(cmp)*>& s) {
  int x = circles[i].x / r_divide_glob, y = circles[i].y / r_divide_glob;
  for (int x2 = x - 2; x2 <= x + 2; x2++) {
    for (int y2 = y - 2; y2 <= y + 2; y2++) {
      pair<int, int> it = {x2, y2};
      if (!guysAtPosition.count(it)) {
        continue;
      }
      vector<int> dl;
      for (auto &j : guysAtPosition[it]) {
        if (doIntersect(circles[i], circles[j])) {
          ret[j] = i;
          s.erase(j);
          dl.push_back(j);
        }
      }
      for (auto &j : dl) {
        guysAtPosition[it].erase(j);
      }
    }
  }
}

int main() {
  if (home == 0) {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  } else {
    freopen ("input.txt", "r", stdin);
  }

  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> circles[i].x >> circles[i].y >> circles[i].r;
    circles[i].x += INF;
    circles[i].y += INF;
  }

  for (int i = 1; i <= n; i++) {
    s.insert(i);
  }
  int max_radius = circles[1].r;
  for (int i = 2; i <= n; i++) {
    max_radius = max(max_radius, circles[i].r);
  }
  place(max_radius, s);
  while (!s.empty()) {
    int i = *s.begin();
    if (circles[i].r <= max_radius / 2) {
      max_radius = circles[i].r;
      place(max_radius, s);
    }
    elim(i, s);
  }

  for (int i = 1; i <= n; i++) {
    cout << ret[i] << " ";
  }
  cout << "\n";

  return 0;
}

Compilation message (stderr)

circle_selection.cpp: In function 'void elim(int, std::set<int, bool (*)(int, int)>&)':
circle_selection.cpp:68:35: error: no matching function for call to 'std::vector<int>::erase(int&)'
   68 |         guysAtPosition[it].erase(j);
      |                                   ^
In file included from /usr/include/c++/10/vector:67,
                 from /usr/include/c++/10/functional:62,
                 from /usr/include/c++/10/pstl/glue_algorithm_defs.h:13,
                 from /usr/include/c++/10/algorithm:74,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:65,
                 from circle_selection.cpp:3:
/usr/include/c++/10/bits/stl_vector.h:1430:7: note: candidate: 'std::vector<_Tp, _Alloc>::iterator std::vector<_Tp, _Alloc>::erase(std::vector<_Tp, _Alloc>::const_iterator) [with _Tp = int; _Alloc = std::allocator<int>; std::vector<_Tp, _Alloc>::iterator = std::vector<int>::iterator; std::vector<_Tp, _Alloc>::const_iterator = std::vector<int>::const_iterator]'
 1430 |       erase(const_iterator __position)
      |       ^~~~~
/usr/include/c++/10/bits/stl_vector.h:1430:28: note:   no known conversion for argument 1 from 'int' to 'std::vector<int>::const_iterator'
 1430 |       erase(const_iterator __position)
      |             ~~~~~~~~~~~~~~~^~~~~~~~~~
/usr/include/c++/10/bits/stl_vector.h:1457:7: note: candidate: 'std::vector<_Tp, _Alloc>::iterator std::vector<_Tp, _Alloc>::erase(std::vector<_Tp, _Alloc>::const_iterator, std::vector<_Tp, _Alloc>::const_iterator) [with _Tp = int; _Alloc = std::allocator<int>; std::vector<_Tp, _Alloc>::iterator = std::vector<int>::iterator; std::vector<_Tp, _Alloc>::const_iterator = std::vector<int>::const_iterator]'
 1457 |       erase(const_iterator __first, const_iterator __last)
      |       ^~~~~
/usr/include/c++/10/bits/stl_vector.h:1457:7: note:   candidate expects 2 arguments, 1 provided
circle_selection.cpp: In function 'int main()':
circle_selection.cpp:78:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |     freopen ("input.txt", "r", stdin);
      |     ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~