Submission #895427

#	Time	Username	Problem	Language	Result	Execution time	Memory
895427		MilosMilutinovic	Circle selection (APIO18_circle_selection)	C++14	37 / 100	3068 ms	879036 KiB

circle_selection

#include <bits/stdc++.h>

using namespace std;

const int N = 4e6;

vector<pair<long long, int>> vec[N];
vector<int> qv;
vector<int> mn[N];
vector<int> mx[N];
vector<int> fa[N];
vector<bool> rem[N];

void Insert(int x, int l, int r, int i, pair<long long, int> v) {
  vec[x].push_back(v);
  if (l == r) {
    return;
  }
  int mid = l + r >> 1;
  if (i <= mid) {
    Insert(x << 1, l, mid, i, v);
  } else {
    Insert(x << 1 | 1, mid + 1, r, i, v);
  }
}

void Build(int x, int l, int r) {
  sort(vec[x].begin(), vec[x].end());
  int k = (int) vec[x].size();
  mn[x] = vector<int>(k);
  mx[x] = vector<int>(k);
  fa[x] = vector<int>(k);
  rem[x] = vector<bool>(k);
  iota(mn[x].begin(), mn[x].end(), 0);
  iota(mx[x].begin(), mx[x].end(), 0);
  iota(fa[x].begin(), fa[x].end(), 0);
  if (l == r) {
    return;
  }
  int mid = l + r >> 1;
  Build(x << 1, l, mid);
  Build(x << 1 | 1, mid + 1, r);
}

void Unite(int x, int a, int b) {
  a = fa[x][a];
  b = fa[x][b];
  if (a == b) {
    return;
  }
  if (mx[x][a] - mn[x][a] > mx[x][b] - mn[x][b]) {
    swap(a, b);
  }
  for (int i = mn[x][a]; i <= mx[x][a]; i++) {
    fa[x][i] = b;
  }
  mx[x][b] = max(mx[x][b], mx[x][a]);
  mn[x][b] = min(mn[x][b], mn[x][b]);
}

void Delete(int x, int l, int r, int i, pair<long long, int> v) {
  int idx = (int) (lower_bound(vec[x].begin(), vec[x].end(), v) - vec[x].begin());
  rem[x][idx] = true;
  if (idx > 0 && rem[x][idx - 1]) {
    Unite(x, idx - 1, idx);
  }
  if (idx + 1 < (int) vec[x].size() && rem[x][idx + 1]) {
    Unite(x, idx, idx + 1);
  }
  if (l == r) {
    return;
  }
  int mid = l + r >> 1;
  if (i <= mid) {
    Delete(x << 1, l, mid, i, v);
  } else {
    Delete(x << 1 | 1, mid + 1, r, i, v);
  }
}

void Query(int x, int l, int r, int ll, int rr, long long L, long long R) {
  if (ll <= l && r <= rr) {
    int idx = (int) (lower_bound(vec[x].begin(), vec[x].end(), make_pair(L, -1)) - vec[x].begin());
    while (idx < (int) vec[x].size() && vec[x][idx].first <= R) {
      if (rem[x][idx]) {
        idx = mx[x][fa[x][idx]] + 1;
        continue;
      }
      qv.push_back(vec[x][idx].second);
      idx += 1;
    }
    return;
  }
  int mid = l + r >> 1;
  if (rr <= mid) {
    Query(x << 1, l, mid, ll, rr, L, R);
  } else if (ll > mid) {
    Query(x << 1 | 1, mid + 1, r, ll, rr, L, R);
  } else {
    Query(x << 1, l, mid, ll, rr, L, R);
    Query(x << 1 | 1, mid + 1, r, ll, rr, L, R);
  }
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  vector<long long> x(n), y(n), r(n);
  for (int i = 0; i < n; i++) {
    cin >> x[i] >> y[i] >> r[i];
  }
  vector<int> order(n);
  iota(order.begin(), order.end(), 0);
  sort(order.begin(), order.end(), [&](int i, int j) {
    if (r[i] != r[j]) {
      return r[i] > r[j];
    } else {
      return i < j;
    }
  });
  vector<long long> xs;
  for (int i = 0; i < n; i++) {
    xs.push_back(x[i] - 2 * r[i]);
    xs.push_back(x[i]);
    xs.push_back(x[i] + 2 * r[i]);
  }
  sort(xs.begin(), xs.end());
  xs.erase(unique(xs.begin(), xs.end()), xs.end());
  int k = (int) xs.size();
  vector<int> res(n);
  for (int i = 0; i < n; i++) {
    res[i] = i;
    int p = (int) (lower_bound(xs.begin(), xs.end(), x[i]) - xs.begin());
    Insert(1, 0, k - 1, p, make_pair(y[i], i));
  }
  Build(1, 0, k - 1);
  for (int i : order) {
    if (res[i] != i) {
      continue;
    }
    qv.clear();
    int p = (int) (lower_bound(xs.begin(), xs.end(), x[i]) - xs.begin());
    Delete(1, 0, k - 1, p, make_pair(y[i], i));
    int L = (int) (lower_bound(xs.begin(), xs.end(), x[i] - 2 * r[i]) - xs.begin());
    int R = (int) (lower_bound(xs.begin(), xs.end(), x[i] + 2 * r[i]) - xs.begin());
    Query(1, 0, k - 1, L, R, y[i] - 2 * r[i], y[i] + 2 * r[i]);
    for (int j : qv) {
      if ((x[i] - x[j]) * 1LL * (x[i] - x[j]) + (y[i] - y[j]) * 1LL * (y[i] - y[j]) <= (r[i] + r[j]) * 1LL * (r[i] + r[j])) {
        res[j] = i;
        Delete(1, 0, k - 1, (int) (lower_bound(xs.begin(), xs.end(), x[j]) - xs.begin()), make_pair(y[j], j));
      }
    }
  }
  for (int i = 0; i < n; i++) {
    cout << res[i] + 1 << " ";
  }
  return 0;
}

Compilation message (stderr)

circle_selection.cpp: In function 'void Insert(int, int, int, int, std::pair<long long int, int>)':
circle_selection.cpp:19:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   19 |   int mid = l + r >> 1;
      |             ~~^~~
circle_selection.cpp: In function 'void Build(int, int, int)':
circle_selection.cpp:40:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   40 |   int mid = l + r >> 1;
      |             ~~^~~
circle_selection.cpp: In function 'void Delete(int, int, int, int, std::pair<long long int, int>)':
circle_selection.cpp:73:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   73 |   int mid = l + r >> 1;
      |             ~~^~~
circle_selection.cpp: In function 'void Query(int, int, int, int, int, long long int, long long int)':
circle_selection.cpp:94:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   94 |   int mid = l + r >> 1;
      |             ~~^~~

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