#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <algorithm>
#include <vector>
#include <cassert>
#include <cmath>
#include <cstring>
/*
*
* Splay tree / sweeping by jay0202
* Geometry by crimson231
*
*/
//#define JAY_MODULE_DEBUG
//#define CRIMSON_MODULE_DEBUG
typedef long long ll;
typedef double ld;
typedef std::pair<int, int> pi;
typedef std::vector<int> Vint;
typedef std::vector<ld> Vld;
const int LEN = 1e5 + 1;
int N;
ll memo[LEN];
std::vector<int> g[LEN]; // above lines
struct Pos {
int x, y;
Pos(int X = 0, int Y = 0) : x(X), y(Y) {}
bool operator == (const Pos& p) const { return x == p.x && y == p.y; }
bool operator != (const Pos& p) const { return x != p.x || y != p.y; }
bool operator < (const Pos& p) const { return x == p.x ? y < p.y : x < p.x; }
bool operator <= (const Pos& p) const { return x == p.x ? y <= p.y : x <= p.x; }
Pos operator + (const Pos& p) const { return { x + p.x, y + p.y }; }
Pos operator - (const Pos& p) const { return { x - p.x, y - p.y }; }
Pos operator * (const int& n) const { return { x * n, y * n }; }
Pos operator / (const int& n) const { return { x / n, y / n }; }
ll operator * (const Pos& p) const { return (ll)x * p.x + (ll)y * p.y; }
ll operator / (const Pos& p) const { return (ll)x * p.y - (ll)y * p.x; }
Pos operator ^ (const Pos& p) const { return { x * p.x, y * p.y }; }
Pos& operator += (const Pos& p) { x += p.x; y += p.y; return *this; }
Pos& operator -= (const Pos& p) { x -= p.x; y -= p.y; return *this; }
Pos& operator *= (const int& scale) { x *= scale; y *= scale; return *this; }
Pos& operator /= (const int& scale) { x /= scale; y /= scale; return *this; }
Pos operator - () const { return { -x, -y }; }
Pos operator ~ () const { return { -y, x }; }
Pos operator ! () const { return { y, x }; }
ll xy() const { return (ll)x * y; }
ll Euc() const { return (ll)x * x + (ll)y * y; }
int Man() const { return std::abs(x) + std::abs(y); }
ld mag() const { return hypot(x, y); }
ld rad() const { return atan2(y, x); }
friend ld rad(const Pos& p1, const Pos& p2) { return atan2l(p1 / p2, p1 * p2); }
int quad() const { return y > 0 || y == 0 && x >= 0; }
friend bool cmpq(const Pos& a, const Pos& b) { return (a.quad() != b.quad()) ? a.quad() < b.quad() : a / b > 0; }
friend std::istream& operator >> (std::istream& is, Pos& p) { is >> p.x >> p.y; return is; }
friend std::ostream& operator << (std::ostream& os, const Pos& p) { os << p.x << " " << p.y; return os; }
} pos[LEN];
const Pos O = Pos(0, 0);
const Pos INVAL = Pos(-1, -1);
typedef std::vector<Pos> Polygon;
ll cross(const Pos& d1, const Pos& d2, const Pos& d3) { return (d2 - d1) / (d3 - d2); }
ll cross(const Pos& d1, const Pos& d2, const Pos& d3, const Pos& d4) { return (d2 - d1) / (d4 - d3); }
ll dot(const Pos& d1, const Pos& d2, const Pos& d3) { return (d2 - d1) * (d3 - d2); }
ll dot(const Pos& d1, const Pos& d2, const Pos& d3, const Pos& d4) { return (d2 - d1) * (d4 - d3); }
int ccw(const Pos& d1, const Pos& d2, const Pos& d3) { ll ret = cross(d1, d2, d3); return ret < 0 ? -1 : !!ret; }
int ccw(const Pos& d1, const Pos& d2, const Pos& d3, const Pos& d4) { ll ret = cross(d1, d2, d3, d4); return ret < 0 ? -1 : !!ret; }
bool on_seg_strong(const Pos& d1, const Pos& d2, const Pos& d3) { return !ccw(d1, d2, d3) && dot(d1, d3, d2) >= 0; }
bool on_seg_weak(const Pos& d1, const Pos& d2, const Pos& d3) { return !ccw(d1, d2, d3) && dot(d1, d3, d2) > 0; }
bool collinear(const Pos& d1, const Pos& d2, const Pos& d3, const Pos& d4) { return !ccw(d1, d2, d3) && !ccw(d1, d2, d4); }
bool intersect(const Pos& s1, const Pos& s2, const Pos& d1, const Pos& d2, const bool f = 1) {
//f : include end of seg, !f : ignore end of seg
bool f1 = ccw(s1, s2, d1) * ccw(s2, s1, d2) > 0;
bool f2 = ccw(d1, d2, s1) * ccw(d2, d1, s2) > 0;
if (!f) return f1 && f2;
bool f3 = on_seg_strong(s1, s2, d1) ||
on_seg_strong(s1, s2, d2) ||
on_seg_strong(d1, d2, s1) ||
on_seg_strong(d1, d2, s2);
return (f1 && f2) || f3;
}
bool inner_check(Pos p0, Pos p1, Pos p2, const Pos& t) {
if (ccw(p0, p1, p2) < 0) std::swap(p1, p2);
return ccw(p0, p1, t) >= 0 && ccw(p1, p2, t) >= 0 && ccw(p2, p0, t) >= 0;
}
ll area(Pos H[], const int& sz) {
ll ret = 0;
for (int i = 0; i < sz; i++) {
Pos cur = H[i], nxt = H[(i + 1) % sz];
ret += cross(O, cur, nxt);
}
return ret;
}
ll area(std::vector<Pos>& H) {
ll ret = 0;
int sz = H.size();
for (int i = 0; i < sz; i++) {
Pos cur = H[i], nxt = H[(i + 1) % sz];
ret += cross(O, cur, nxt);
}
return ret;
}
void norm(Pos H[], const int& sz) {
ll A = area(H, sz);
assert(A);
if (A < 0) std::reverse(H, H + sz);
return;
}
void norm(Polygon& H) {
ll A = area(H);
if (A < 0) std::reverse(H.begin(), H.end());
auto s = std::min_element(H.begin(), H.end());
std::rotate(H.begin(), s, H.end());
}
void move(Pos H[], const Pos& vec) { for (int i = 0; i < N; i++) H[i] += vec; }
void move(Polygon& H, const Pos& vec) {
int sz = H.size();
for (int i = 0; i < sz; i++) H[i] += vec;
}
void rotate() { for (int i = 0; i < N; i++) pos[i] = ~pos[i]; }
void rotate(Polygon& H) {
int sz = H.size();
for (int i = 0; i < sz; i++) H[i] = ~H[i];
}
void mirror() { for (int i = 0; i < N; i++) pos[i].x = -pos[i].x; }
void mirror(Polygon& H) {
int sz = H.size();
for (int i = 0; i < sz; i++) H[i].x = -H[i].x;
}
bool polygon_cmp(const Polygon& A, const Polygon& B) {
int a = A.size(), b = B.size();
if (a != b) return 0;
for (int i = 0; i < a; i++) {
if (A[i] != B[i]) return 0;
}
return 1;
}
bool operator == (const Polygon& p, const Polygon& q) { return polygon_cmp(p, q); }
Polygon make_polygon(int u, int v, Pos s, Pos e) {
Polygon H, tmp;
Vint V;
//std::cout << "fuck:: make poly " << u << " " << v << "\n";
//std::cout << "fuck:: " << s << " " << e << "\n";
H.push_back(e);
H.push_back(s);
for (int i = (u + 1) % N; i != (v + 1) % N; i = (i + 1) % N) {
const Pos& p = pos[i];
if (p != s && p != e) H.push_back(p);
}
int sz = H.size();
V.resize(sz, 0);
for (int i = 0; i < sz; i++) {
const Pos& pre = H[(i - 1 + sz) % sz], cur = H[i], nxt = H[(i + 1) % sz];
if (!ccw(pre, cur, nxt)) V[i] = 1;
}
for (int i = 0; i < sz; i++) if (!V[i]) tmp.push_back(H[i]);
return tmp;
}
bool all_polygon_cmp(int u, int v, Pos s, Pos e) {
Polygon A = make_polygon(u, v, s, e);
Polygon B = make_polygon(v, u, e, s);
#ifdef CRIMSON_MODULE_DEBUG
std::cout << "FUCK:: s:: " << s << " e:: " << e << "\n";
std::cout << "FUCK::\n";
std::cout << "A = [\n";
for (Pos& p : A) {
std::cout << "(" << p.x << ", " << p.y << "), \n";
}
std::cout << "]\n";
std::cout << "B = [\n";
for (Pos& p : B) {
std::cout << "(" << p.x << ", " << p.y << "), \n";
}
std::cout << "]\n";
#endif
if (A.size() != B.size()) return 0;
norm(A), norm(B);
Pos b = *std::min_element(B.begin(), B.end());
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 4; j++) {
rotate(A);
norm(A);
Pos a = *std::min_element(A.begin(), A.end());
move(A, b - a);
if (A == B) return 1;
}
mirror(A);
}
return 0;
}
struct Line {
int y; // y coord
int l, r; // x coords (l <= r)
/// <summary>
/// sort lines
/// <para>
/// 1. compare y.
/// </para>
/// <para>
/// 2. if y coords are equal, compare x.
/// </para>
/// </summary>
/// <param name="o">other</param>
/// <returns>bool</returns>
bool operator<(const Line& o) const {
return y == o.y ? l < o.l : y > o.y;
}
};
int Q;
/// <summary>
/// event horizon
/// </summary>
struct Event {
int i; // index of event line
int d; // flag value. (0: insert range, 1: query range)
Line l; // line
bool operator<(const Event& r) const { return l < r.l; }
} events[LEN];
/// <summary>
/// segment struct defined to use in SplayTree node.
/// simplified version of line event (ommited y coord)
/// </summary>
struct Seg {
int l, r; // x coords
int i;
Seg(int l = 0, int r = 0, int i = 0) : l(l), r(r), i(i) {}
/// <summary>
/// only compare x coords
/// </summary>
/// <param name="o">other</param>
/// <returns></returns>
bool operator<(const Seg& o) const {
return l < o.l;
}
};
std::vector<Seg> Segs;
void match(int u, int v, int l, int r) {
#ifdef JAY_MODULE_DEBUG
std::cout << "facing pair: " << u << ' ' << v << '\n';
std::cout << " facing range: " << l << ' ' << r << '\n';
#endif
g[u].push_back(v);
Segs.push_back(Seg(l, r, v));
}
bool find_split(const int i, const Seg& S, Pos& s, Pos& e) {
int j = i, k = S.i;
Pos& J = pos[j], & K = pos[k];
bool f = 0;
if (k < j) f = 1, std::swap(j, k);
ll a1 = memo[k] - memo[j];
//std::cout << "FUCK:: a1:: " << a1 << "\n";
//std::cout << "FUCK:: A :: " << memo[N] << "\n";
if (f) a1 = memo[N] - a1;
Pos& pl = pos[i], & pr = pos[(i + 1) % N];
assert(pl.x < pr.x);
int r = std::min(pr.x, S.r);
int l = std::max(pl.x, S.l);
int yh = pos[S.i].y;
int yl = pl.y;
int h = yh - yl;
Pos b1 = Pos(r, yh), b2 = Pos(l, yh), b3 = Pos(l, yl), b4 = Pos(r, yl);
/*
sl b2 b1 sr K -- a1
pl b3 b4 pr J --
*/
ll amax = a1 + K / b2 + b2 / b3 + b3 / J;
ll amin = a1 + K / b1 + b1 / b4 + b4 / J;
ll a2 = memo[N] >> 1;
//std::cout << "DEBUG:: amin:: " << amin << " amax:: " << amax << " a2:: " << a2 << "\n";
if (amin <= a2 && a2 <= amax) {
ll box = a2 - amin;
ll w = box / h;
if (w & 1) return 0;
s = Pos(r - (w >> 1), pr.y);
e = Pos(r - (w >> 1), pos[S.i].y);
assert(s < e);
return 1;
}
return 0;
}
class SplayTree {
struct Node {
Node* l;
Node* r;
Node* p;
Seg val;
Node(int l, int r, int i) : l(0), r(0), p(0) { val = { l, r, i }; }
~Node() { if (l) delete l; if (r) delete r; }
} *root;
void rotate(Node* x) {
Node* p = x->p;
if (!p) return;
Node* b = 0;
if (x == p->l) {
p->l = b = x->r;
x->r = p;
}
else {
p->r = b = x->l;
x->l = p;
}
x->p = p->p;
p->p = x;
if (b) b->p = p;
(x->p ? p == x->p->l ? x->p->l : x->p->r : root) = x;
}
void splay(Node* x) {
while (x->p) {
Node* p = x->p;
Node* g = p->p;
if (g) {
if ((x == p->l) == (p == g->l)) rotate(p);
else rotate(x);
}
rotate(x);
}
}
/// <summary>
/// find a line that has nearest r coord from l.
/// </summary>
/// <param name="l">: target x coord</param>
/// <returns></returns>
Node* find(int l) {
if (!root) return 0;
Node* p = root;
while (1) {
if (p->val.r == l) break;
if (p->val.r < l) {
if (!p->r) {
break;
}
p = p->r;
}
else {
if (!p->l) {
break;
}
p = p->l;
}
}
splay(p);
return p;
}
public:
SplayTree() : root(0) {}
~SplayTree() { if (root) delete root; }
void insert(int l, int r, int i) {
if (!root) {
root = new Node(l, r, i);
return;
}
Node* p = root;
Node** pp;
while (1) {
if (p->val.l < l) {
if (!p->r) {
pp = &p->r;
break;
}
p = p->r;
}
else {
if (!p->l) {
pp = &p->l;
break;
}
p = p->l;
}
}
Node* x = new Node(l, r, i);
*pp = x;
x->p = p;
splay(x);
}
void pop(Node* ptr) {
if (!ptr) return;
splay(ptr);
Node* p = root;
if (p->l && p->r) {
root = p->l; root->p = 0;
Node* l = root;
while (l->r) l = l->r;
l->r = p->r;
p->r->p = l;
}
else if (p->l) root = p->l, root->p = 0;
else if (p->r) root = p->r, root->p = 0;
else root = 0;
p->l = p->r = 0;
delete p;
}
/// <summary>
/// find leftmost line first.
/// if line is splitted by query segment, then insert new segment and return.
/// else, find right segments while r coord of segment is smaller than query r.
/// </summary>
/// <param name="l">x coord</param>
/// <param name="r">x coord</param>
/// <param name="i">line index</param>
void query(int l, int r, int i) {
assert(root);
Node* x = find(l); // first segment
assert(x->val.l <= l);
if (x->val.r < l) { // if segment is out of range: find very right one
x = x->r;
while (x->l) x = x->l;
}
if (x->val.r > r) { // if splitted
match(i, x->val.i, l, r);
int nl = r, nr = x->val.r, ni = x->val.i;
x->val.r = l; // split
if (x->val.l == l) pop(x); // and pop if left is covered.
insert(nl, nr, ni); // insert new right segment
return;
}
match(i, x->val.i, l, x->val.r); // match two of them
x->val.r = l; // left side of segment is covered by query segment
if (x->val.r == x->val.l) pop(x); // pop if all range covered
while (x = find(l)) { // find leftmost
//if (x->val.r == l) break;
if (x->val.r <= l) { // if leftmost is out of range
if (!x->r) return; // no more right segment
x = x->r;
while (x->l) x = x->l; // find very right segment
}
if (x->val.l > r) return;
match(i, x->val.i, x->val.l, std::min(r, x->val.r)); // match two of them
if (x->val.r > r) { // if right segment is not covered totally
x->val.l = r;
break; // then, query range is sweeped. return
}
else pop(x); // else, a segment is sweeped. pop and find next segment
}
}
} sp;
bool vertical_split(Pos& s, Pos& e) {
memo[0] = 0;
for (int i = 0; i < N; i++) {
memo[i + 1] = memo[i] + pos[i] / pos[(i + 1) % N];
}
// horizontal check
Q = 0;
for (int i = 0; i < N; ++i) {
int j = (i + 1) % N;
if (pos[i].y == pos[j].y) {
if (pos[i].x < pos[j].x) { // right halfline
events[Q++] = { i, 1, { pos[i].y, pos[i].x, pos[j].x } };
}
if (pos[i].x > pos[j].x) { // left halfline
events[Q++] = { i, 0, { pos[i].y, pos[j].x, pos[i].x } };
}
}
}
std::sort(events, events + Q);
for (int i = 0; i < Q; ++i) {
//std::cout << (events[i].d == 0 ? "insert" : "query") << " segment: (h, l, r) ";
//std::cout << events[i].l.y << ' ' << events[i].l.l << ' ' << events[i].l.r << '\n';
if (events[i].d == 0) sp.insert(events[i].l.l, events[i].l.r, events[i].i);
if (events[i].d == 1) {
Segs.clear();
sp.query(events[i].l.l, events[i].l.r, events[i].i);
for (Seg& S : Segs) {
//std::cout << "segs::\n";
if (find_split(events[i].i, S, s, e)) {
//std::cout << "polygon cmp before::\n";
if (all_polygon_cmp(events[i].i, S.i, s, e)) return 1;
//std::cout << "polygon cmp after::\n";
}
}
}
}
return 0;
}
void solve() {
//freopen("demarcation.in copy.4", "r", stdin);
//freopen("demarcation.out", "w", stdout);
std::cin.tie(0)->sync_with_stdio(0);
//std::cout.tie(0);
std::cin >> N;
for (int i = 0; i < N; ++i) std::cin >> pos[i].x >> pos[i].y;
ll A = area(pos, N);
assert(A);
if (A < 0) std::reverse(pos, pos + N);
A *= -1;
A >>= 1;
#ifdef CRIMSON_MODULE_DEBUG
std::cout << "FUCK::\n";
std::cout << "pos = [\n";
for (int i = 0; i < N; i++) {
std::cout << "(" << pos[i].x << ", " << pos[i].y << "), \n";
}
std::cout << "]\n";
#endif
if (A & 1) { std::cout << "NO\n"; return; }
Pos s, e;
if (vertical_split(s, e)) {
//std::cout << "YES\n";
std::cout << s << " " << e << "\n";
return;
}
rotate();
//std::cout << "FUCK::\n";
if (vertical_split(s, e)) {
//std::cout << "YES\n";
std::cout << -~s << " " << - ~e << "\n";
return;
}
//std::cout << "FUCK::\n";
std::cout << "NO\n";
return;
}
int main() { solve(); return 0; }//boj10098 Demarcation
/*
8
0 0
6 0
6 2
5 2
5 1
1 1
1 4
0 4
void solve() {
freopen("demarcation.in.1", "r", stdin);
freopen("demarcation.out", "w", stdout);
std::cin.tie(0)->sync_with_stdio(0);
//std::cout.tie(0);
std::cin >> N;
for (int i = 0; i < N; ++i) std::cin >> pos[i].x >> pos[i].y;
norm(pos, N);
// horizontal check
Q = 0;
for (int i = 0; i < N; ++i) {
int j = (i + 1) % N;
if (pos[i].y == pos[j].y) {
if (pos[i].x < pos[j].x) { // right halfline
events[Q++] = { i, 1, { pos[i].y, pos[i].x, pos[j].x } };
}
if (pos[i].x > pos[j].x) { // left halfline
events[Q++] = { i, 0, { pos[i].y, pos[j].x, pos[i].x } };
}
}
}
std::sort(events, events + Q);
for (int i = 0; i < Q; ++i) {
std::cout << (events[i].d == 0 ? "insert" : "query") << " segment: (h, l, r) ";
std::cout << events[i].l.y << ' ' << events[i].l.l << ' ' << events[i].l.r << '\n';
if (events[i].d == 0) sp.insert(events[i].l.l, events[i].l.r, events[i].i);
if (events[i].d == 1) sp.query(events[i].l.l, events[i].l.r, events[i].i);
}
#ifdef JAY_MODULE_DEBUG
std::cout << "points = [\n";
for (int i = 0; i < N; i++) {
std::cout << " (" << pos[i].x << ", " << pos[i].y << "), \n";
}
std::cout << "]\n";
for (int i = 0; i <= N; ++i) {
if (g[i].size()) {
std::cout << "right half-line from " << i << '\n';
std::cout << " matching left half-lines from: ";
for (const int& j : g[i]) std::cout << j << ' ';
std::cout << '\n';
}
}
#endif
}
*/
Compilation message
demarcation.cpp: In member function 'int Pos::quad() const':
demarcation.cpp:56:47: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
56 | int quad() const { return y > 0 || y == 0 && x >= 0; }
| ~~~~~~~^~~~~~~~~
demarcation.cpp: In member function 'void SplayTree::query(int, int, int)':
demarcation.cpp:431:18: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
431 | while (x = find(l)) { // find leftmost
| ~~^~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
4 ms |
5976 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
5212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
5212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
3 ms |
5980 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
