Submission #895449

#	Time	Username	Problem	Language	Result	Execution time	Memory
895449		MilosMilutinovic	Circle selection (APIO18_circle_selection)	C++14	37 / 100	3088 ms	860852 KiB

circle_selection

#include <bits/stdc++.h>
 
using namespace std;
 
const int MAX = 3e5;
const int N = 4e6;
 
long long x[MAX], y[MAX], r[MAX];
int res[MAX], len, cur;
vector<pair<long long, int>> vec[N];
vector<int> xs;
vector<int> mn[N];
vector<int> mx[N];
vector<int> fa[N];
vector<bool> rem[N];
 
void Insert(int i, pair<long long, int> v) {
  for (int x = i + len; x > 0; x >>= 1) {
    vec[x].push_back(v);
  }
}
 
void Build() {
  for (int x = 1; x < 2 * len; x++) {
    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);
  }
}
 
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][a]);
}
 
void Delete(int i, pair<long long, int> v) {
  for (int x = i + len; x > 0; x >>= 1) {
    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);
    }
  }
}
 
void Check(int idx) {
  if ((x[cur] - x[idx]) * 1LL * (x[cur] - x[idx]) + (y[cur] - y[idx]) * 1LL * (y[cur] - y[idx]) <= (r[cur] + r[idx]) * 1LL * (r[cur] + r[idx])) {
    res[idx] = cur;
    Delete((int) (lower_bound(xs.begin(), xs.end(), x[idx]) - xs.begin()), make_pair(y[idx], idx));
  }
}
 
void Add(int x, long long L, long long R) {
  int low = 0, high = (int) vec[x].size() - 1, idx = high + 1;
  while (low <= high) {
    int mid = low + high >> 1;
    if (vec[x][mid].first >= L) {
      idx = mid;
      high = mid - 1;
    } else {
      low = mid + 1;
    }
  }
  //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;
    }
    Check(vec[x][idx].second);
    idx += 1;
  }
}
 
void Query(int l, int r, long long L, long long R) {
  for (l += len, r += len + 1; l < r; l >>= 1, r >>= 1) {
    if (l & 1) {
      Add(l++, L, R);
    }
    if (r & 1) {
      Add(--r, L, R);
    }
  }
}
 
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> 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;
    }
  });
  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();
  len = 1;
  while (len < k) {
    len *= 2;
  }
  for (int i = 0; i < n; i++) {
    res[i] = i;
    int p = (int) (lower_bound(xs.begin(), xs.end(), x[i]) - xs.begin());
    Insert(p, make_pair(y[i], i));
  }
  Build();
  for (int i : order) {
    if (res[i] != i) {
      continue;
    }
    cur = i;
    int p = (int) (lower_bound(xs.begin(), xs.end(), x[i]) - xs.begin());
    Delete(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(L, R, y[i] - 2 * r[i], y[i] + 2 * r[i]);
  }
  for (int i = 0; i < n; i++) {
    cout << res[i] + 1 << " ";
  }
  return 0;
}

Compilation message (stderr)

circle_selection.cpp: In function 'void Add(int, long long int, long long int)':
circle_selection.cpp:76:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   76 |     int mid = low + high >> 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