Files
Codeforces-solutions/2019 China Collegiate Programming Contest Qinhuangdao Onsite/A. Angle Beats.cpp
2026-03-16 20:14:14 -03:00

360 lines
7.6 KiB
C++

/* Problem URL: https://codeforces.com/gym/102361/problem/A */
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template <class T, class comp = less<>>
using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
#define V vector
#define rmin(a, b) a = min(a, b)
#define rmax(a, b) a = max(a, b)
#define rep(i, lim) for (int i = 0; i < (lim); i++)
#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
#define repv(i, v) for (auto &i : (v))
#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
#define sortv(v) sort(v.begin(), v.end())
#define all(v) (v).begin(), (v).end()
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vvvvi = vector<vvvi>;
using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vvvvl = vector<vvvl>;
template<class v>
auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
os << vec[0];
for (size_t i = 1; i < vec.size(); i++) {
os << ' ' << vec[i];
}
os << '\n';
return os;
}
template<class v>
auto operator>>(istream &is, vector<v> &vec)->istream& {
for (auto &i : vec) {
is >> i;
}
return is;
}
template<class v>
auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
for (auto &i : vec) {
os << i[0];
for (size_t j = 1; j < i.size(); j++) {
os << ' ' << i[j];
}
os << '\n';
}
return os;
}
template<class v>
auto operator>>(istream &is, vector<vector<v>> &vec)->istream& {
for (auto &i : vec) {
for (auto &j : i) {
is >> j;
}
}
return is;
}
const int oo = INT32_MAX >> 1;
const ll OO = INT64_MAX >> 1;
struct pt {
ll x, y;
int c;
pt() = default;
pt(ll x, ll y): x(x), y(y) {}
pt(pt a, int c): x(a.x), y(a.y), c(c) {}
friend istream &operator >> (istream &is, pt &a) {
is >> a.x >> a.y;
return is;
}
pt operator - (pt b) {
return pt(x - b.x, y - b.y);
}
ll operator * (pt b) {
return x * b.x + y * b.y;
}
ll operator ^ (pt b) {
return x * b.y - y * b.x;
}
};
int ccw(pt a, pt b, pt c)
{
ll r = (b - a) ^ (c - b);
return (r > 0) - (r < 0);
}
ll cdot(pt a, pt b, pt c)
{
return (b - a) * (c - a);
}
int quad(pt a)
{
static int q[][2] = {{0, 1}, {3, 2}};
return q[a.x < 0][a.y < 0];
}
bool polar_cmp(pt a, pt b)
{
if (quad(a) != quad(b)) {
return quad(a) < quad(b);
}
return ccw(pt(0, 0), a, b) < 0;
}
void pre()
{
}
#define TEST 0
void solve()
{
int n, q;
cin >> n >> q;
V<pt> pts(n + q);
cin >> pts;
vl ans(q);
vi inv(n);
vi va(q);
vi ev(n + q);
iota(all(inv), 0);
iota(all(va), n);
iota(all(ev), 0);
rep(i, n) {
auto cmp = [&](int j, int k) {
if (j == i) {
return false;
}
if (k == i) {
return true;
}
return polar_cmp(pts[j] - pts[i], pts[k] - pts[i]);
};
sort(all(va), cmp);
sort(all(inv), cmp);
int sz = inv.size() - 1;
V<pair<int, ll>> tmp;
int c = 1;
nrep(j, 1, sz) {
if (ccw(pts[i], pts[inv[j - 1]], pts[inv[j]]) == 0) {
c++;
continue;
}
tmp.emplace_back(inv[j - 1], c);
c = 1;
}
tmp.emplace_back(inv.end()[-2], c);
int j = 0;
int k = 0;
auto valid1 = [&]() {
auto p1 = pts[va[j]];
if (ccw(pts[i], p1, pts[inv[0]]) > 0 && ccw(pts[i], p1, pts[inv.end()[-2]]) > 0) {
return false;
}
if (ccw(pts[i], p1, pts[inv[0]]) < 0 && ccw(pts[i], p1, pts[inv.end()[-2]]) < 0 &&
cdot(pts[i], p1, pts[inv[0]]) > 0 && cdot(pts[i], p1, pts[inv.end()[-2]]) > 0) {
return false;
}
return true;
};
while (j < va.size()) {
auto p1 = pts[va[j]];
auto p2 = pts[tmp[k % tmp.size()].first];
if (!valid1()) {
j++;
continue;
}
if (ccw(pts[i], p1, p2) > 0) {
k++;
continue;
}
ll dot = cdot(pts[i], p1, p2);
if (dot < 0) {
j++;
continue;
}
if (dot > 0) {
auto p3 = pts[tmp[(k + 1) % tmp.size()].first];
if (ccw(pts[i], p1, p3) > 0 || cdot(pts[i], p1, p3) < 0) {
j++;
continue;
}
k++;
continue;
}
ans[va[j] - n] += tmp[k % tmp.size()].second;
j++;
}
auto valid2 = [&]() {
auto p1 = pts[va[j]];
if (ccw(pts[i], p1, pts[inv[0]]) < 0 && ccw(pts[i], p1, pts[inv.end()[-2]]) < 0) {
return false;
}
if (ccw(pts[i], p1, pts[inv[0]]) > 0 && ccw(pts[i], p1, pts[inv.end()[-2]]) > 0 &&
cdot(pts[i], p1, pts[inv[0]]) > 0 && cdot(pts[i], p1, pts[inv.end()[-2]]) > 0) {
return false;
}
return true;
};
j = va.size() - 1;
k = tmp.size() - 1;
auto kpos = [&]() {
return (k % tmp.size() + tmp.size()) % tmp.size();
};
while (j >= 0) {
auto p1 = pts[va[j]];
auto p2 = pts[tmp[kpos()].first];
if (!valid2()) {
j--;
continue;
}
if (ccw(pts[i], p1, p2) < 0) {
k--;
continue;
}
ll dot = cdot(pts[i], p1, p2);
if (dot < 0) {
j--;
continue;
}
if (dot > 0) {
auto p3 = pts[tmp[((k - 1) % tmp.size() + tmp.size()) % tmp.size()].first];
if (ccw(pts[i], p1, p3) > 0 || cdot(pts[i], p1, p3) < 0) {
j--;
continue;
}
k--;
continue;
}
ans[va[j] - n] += tmp[kpos()].second;
j--;
}
}
nrep(i, n, n + q) {
auto cmp = [&](int j, int k) {
return polar_cmp(pts[j] - pts[i], pts[k] - pts[i]);
};
sort(all(inv), cmp);
V<pair<int, ll>> tmp;
int c = 1;
nrep(j, 1, n) {
if (ccw(pts[i], pts[inv[j - 1]], pts[inv[j]]) == 0) {
c++;
continue;
}
tmp.emplace_back(inv[j - 1], c);
c = 1;
}
tmp.emplace_back(inv.end()[-1], c);
int j = 0;
int k = 0;
while (j < tmp.size()) {
while (k <= j) {
k++;
}
auto p1 = pts[tmp[j].first];
auto p2 = pts[tmp[k % tmp.size()].first];
ll dot = (p1 - pts[i]) * (p2 - pts[i]);
if (ccw(pts[i], p1, p2) >= 0 || dot < 0) {
j++;
continue;
}
if (dot > 0) {
k++;
continue;
}
ans[i - n] += tmp[j].second * tmp[k % tmp.size()].second;
j++;
}
}
repv(i, ans) {
cout << i << '\n';
}
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
pre();
int t;
(TEST && cin >> t) || (t = 1);
while (t--) {
solve();
}
}