Submission #981957

#	Time	Username	Problem	Language	Result	Execution time	Memory
981957		xiaowuc1	Circle selection (APIO18_circle_selection)	C++17	100 / 100	1971 ms	52144 KiB

circle_selection

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cstring>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <unordered_map>
#include <vector>

using namespace std;

// BEGIN NO SAD
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define trav(a, x) for(auto& a : x)
#define all(x) x.begin(), x.end()
#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
typedef vector<int> vi;
#define f first
#define s second
#define derr if(0) cerr
void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
 
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ", "; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? ", " : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#define debug(x...) cerr << "\e[91m"<<__func__<<":"<<__LINE__<<" [" << #x << "] = ["; _print(x); cerr << "\e[39m" << flush;
// END NO SAD

template<class Fun>
class y_combinator_result {
  Fun fun_;
public:
  template<class T>
  explicit y_combinator_result(T &&fun): fun_(std::forward<T>(fun)) {}

  template<class ...Args>
  decltype(auto) operator()(Args &&...args) {
    return fun_(std::ref(*this), std::forward<Args>(args)...);
  }
};

template<class Fun>
decltype(auto) y_combinator(Fun &&fun) {
  return y_combinator_result<std::decay_t<Fun>>(std::forward<Fun>(fun));
}

template<class T>
bool updmin(T& a, T b) {
  if(b < a) {
    a = b;
    return true;
  }
  return false;
}
template<class T>
bool updmax(T& a, T b) {
  if(b > a) {
    a = b;
    return true;
  }
  return false;
}
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<vector<ll>> matrix;

void solve() {
  int n;
  cin >> n;
  vector<array<ll, 4>> circles(n);
  vector<array<ll, 3>> meta(n);
  auto touch = [&](int i, int j) {
    ll x = meta[i][0] - meta[j][0];
    ll y = meta[i][1] - meta[j][1];
    ll r = meta[i][2] + meta[j][2];
    return x*x+y*y <= r*r;
  };
  for(int i = 0; i < n; i++) {
    ll x, y, r;
    cin >> x >> y >> r;
    x += 2e9;
    y += 2e9;
    assert(x >= r);
    assert(y >= r);
    circles[i] = {x, y, r, i};
    meta[i] = {x, y, r};
  }
  sort(all(circles), [&](auto a, auto b) -> bool {
    if(a[2] != b[2]) return a[2] > b[2];
    return a[3] < b[3];
  });
  vector<int> ret(n, -1);
  vector<bool> gone(n);
  int CIRCLE_SIZE = 1 << 30;
  bool dirty = false;
  vector<array<ll, 2>> coords;
  vector<vector<int>> locs;
  for(auto circ: circles) {
    if(gone[circ[3]]) continue;
    while(CIRCLE_SIZE > circ[2]) {
      CIRCLE_SIZE /= 2;
      dirty = true;
    }
    if(dirty) {
      coords.clear();
      locs.clear();
      for(int i = 0; i < n; i++) {
        if(gone[i]) continue;
        auto [x, y, r] = meta[i];
        ll xl = x;
        ll yl = y;
        xl /= CIRCLE_SIZE;
        yl /= CIRCLE_SIZE;
        coords.pb({xl, yl});
      }
      sort(all(coords));
      coords.erase(unique(all(coords)), coords.end());
      locs.resize(sz(coords));
      for(int i = 0; i < n; i++) {
        if(gone[i]) continue;
        auto [x, y, r] = meta[i];
        ll xl = x;
        ll yl = y;
        xl /= CIRCLE_SIZE;
        yl /= CIRCLE_SIZE;
        int tidx = lb(all(coords), array<ll, 2>({xl, yl})) - coords.begin();
        assert(tidx < sz(coords));
        assert(coords[tidx][0] == xl);
        assert(coords[tidx][1] == yl);
        locs[tidx].pb(i);
      }
      dirty = false;
    }
    auto [x, y, r, idx] = circ;
    assert(!gone[idx]);
    ret[idx] = idx;
    gone[idx] = true;
    ll xl = x-r, xr = x+r;
    ll yl = y-r, yr = y+r;
    xl /= CIRCLE_SIZE, yl /= CIRCLE_SIZE;
    xr /= CIRCLE_SIZE, yr /= CIRCLE_SIZE;
    for(ll a = xl-2; a <= xr+2; a++) for(ll b = yl-2; b <= yr+2; b++) {
      int tidx = lb(all(coords), array<ll, 2>({a, b})) - coords.begin();
      if(tidx == sz(coords) || coords[tidx] != array<ll, 2>({a, b})) continue;
      vector<int> nv;
      for(auto out: locs[tidx]) {
        if(gone[out]) continue;
        if(!touch(idx, out)) {
          nv.pb(out);
        }
        else {
          gone[out] = true;
          ret[out] = idx;
        }
      }
      if(sz(nv)) swap(locs[tidx], nv);
    }
  }
  for(int i = 0; i < n; i++) cout << ++ret[i] << " \n"[i == n-1];
}

// what would chika do
// are there edge cases (N=1?)
// are array sizes proper (scaled by proper constant, for example 2* for koosaga tree)
// integer overflow?
// DS reset properly between test cases
// are you doing geometry in floating points
// are you not using modint when you should

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  solve();
}

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