#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define Time (clock() * 1.0 / CLOCKS_PER_SEC)
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
using ld = long double;
template<typename T1, typename T2> bool chkmin(T1& x, T2 y) {
return y < x ? (x = y, true) : false;
}
template<typename T1, typename T2> bool chkmax(T1& x, T2 y) {
return y > x ? (x = y, true) : false;
}
void debug_out() {
cerr << endl;
}
template<typename T1, typename... T2> void debug_out(T1 A, T2... B) {
cerr << ' ' << A;
debug_out(B...);
}
template<typename T> void mdebug_out(T* a, int n) {
for (int i = 0; i < n; ++i)
cerr << a[i] << ' ';
cerr << endl;
}
#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define mdebug(a, n) cerr << #a << ": ", mdebug_out(a, n)
#else
#define debug(...) 1337
#define mdebug(a, n) 1337
#endif
template<typename T> ostream& operator << (ostream& stream, const vector<T>& v) {
for (auto& x : v)
stream << x << ' ';
return stream;
}
template<typename T1, typename T2> ostream& operator << (ostream& stream, const pair<T1, T2>& p) {
return stream << p.first << ' ' << p.second;
}
const int INF32 = 1e9;
using Point = array<int, 2>;
using Segm = Point;
Segm universe_segm;
Segm intersect(const Segm& s1, const Segm& s2) {
return {max(s1[0], s2[0]), min(s1[1], s2[1])};
}
void uintersect(Segm& s1, const Segm& s2) {
chkmax(s1[0], s2[0]);
chkmin(s1[1], s2[1]);
}
bool in(int x, const Segm& s) {
return s[0] <= x && x <= s[1];
}
bool empt(const Segm& s) {
return s[0] > s[1];
}
struct Rect {
Segm s[2];
Rect() {}
void read() {
cin >> s[0][0] >> s[1][0] >> s[0][1] >> s[1][1];
}
bool in(Point P) {
return ::in(P[0], s[0]) && ::in(P[1], s[1]);
}
} universe_rect;
ostream& operator << (ostream& stream, const Rect& r) {
return stream << r.s[0][0] << ' ' << r.s[1][0] << ' ' << r.s[0][1] << ' ' << r.s[1][1];
}
Rect intersect(const Rect& r1, const Rect& r2) {
Rect r3;
for (int a = 0; a < 2; ++a) {
r3.s[a][0] = max(r1.s[a][0], r2.s[a][0]);
r3.s[a][1] = min(r1.s[a][1], r2.s[a][1]);
}
return r3;
}
vector<Point> solve(int k, vector<Rect> rects, vector<Point> points) {
if (rects.empty()) {
while (k--)
points.push_back({0, 0});
return points;
}
Rect I = universe_rect;
for (Rect& r : rects)
I = intersect(I, r);
if (k == 1) {
if (I.s[0][0] > I.s[0][1] || I.s[1][0] > I.s[1][1]) {
return {};
} else {
points.push_back({I.s[0][0], I.s[1][0]});
return points;
}
}
for (int i = 0; i < 2; ++i) {
for (int j = 0; j < 2; ++j) {
Point P{I.s[0][i], I.s[1][j]};
points.push_back(P);
vector<Rect> new_rects;
for (auto r : rects)
if (!r.in(P))
new_rects.push_back(r);
auto res = solve(k - 1, new_rects, points);
if (!res.empty()) {
return res;
}
points.pop_back();
}
}
return {};
}
int32_t main() {
#ifdef LOCAL
freopen("in", "r", stdin);
#endif
ios::sync_with_stdio(0);
cin.tie(0);
universe_rect.s[0][0] = universe_rect.s[1][0] = 0;
universe_rect.s[0][1] = universe_rect.s[1][1] = +INF32;
universe_segm = {0, +INF32};
int n, k;
cin >> n >> k;
vector<int> rv;
vector<Rect> rects(n);
for (auto& r : rects) {
r.read();
for (int a = 0; a < 2; ++a)
for (int b = 0; b < 2; ++b)
rv.push_back(r.s[a][b]);
}
sort(all(rv));
rv.resize(unique(all(rv)) - rv.begin());
int X = rv.size();
for (auto& r : rects)
for (int a = 0; a < 2; ++a) {
assert(r.s[a][0] <= r.s[a][1]);
for (int b = 0; b < 2; ++b)
r.s[a][b] = lower_bound(all(rv), r.s[a][b]) - rv.begin();
assert(r.s[a][0] <= r.s[a][1]);
}
auto easy = solve(k, rects, {});
if (!easy.empty()) {
for (auto P : easy)
cout << rv[P[0]] << ' ' << rv[P[1]] << '\n';
exit(0);
}
assert(k == 4);
Rect I = universe_rect;
for (Rect r : rects)
I = intersect(I, r);
int R = I.s[0][0], L = I.s[0][1];
int U = I.s[1][0], D = I.s[1][1];
assert(L < R);
assert(D < U);
Segm baseL = {D + 1, U - 1};
Segm baseR = {D + 1, U - 1};
Segm baseD = {L + 1, R - 1};
Segm baseU = {L + 1, R - 1};
vector<Segm> prefLR(X + 1, universe_segm);
vector<Segm> suffLR(X + 1, universe_segm);
vector<Segm> prefDU(X + 1, universe_segm); // also prefUD
vector<Segm> prefLU(X + 1, universe_segm);
vector<Segm> suffLD(X + 1, universe_segm);
vector<Segm> prefUR(X + 1, universe_segm);
vector<Segm> prefDR(X + 1, universe_segm);
int minxUD = +INF32;
for (Rect r : rects) {
Segm rx = r.s[0], ry = r.s[1];
int touchL = in(L, rx);
int touchR = in(R, rx);
int touchD = in(D, ry);
int touchU = in(U, ry);
int sum = touchL + touchR + touchD + touchU;
if (sum == 0) throw;
if (sum >= 3) continue;
if (sum == 1) {
if (touchL) {
uintersect(baseL, ry);
} else if (touchR) {
uintersect(baseR, ry);
} else if (touchD) {
uintersect(baseD, rx);
} else { // touchU
uintersect(baseU, rx);
}
} else { // sum = 2
if (touchL && touchR) {
uintersect(prefLR[ry[0]], ry);
uintersect(suffLR[ry[1] + 1], ry);
} else if (touchD && touchU) {
chkmin(minxUD, rx[1]);
uintersect(prefDU[rx[0]], rx);
} else if (touchL && touchU) {
uintersect(prefLU[ry[0]], rx);
} else if (touchL && touchD) {
uintersect(suffLD[ry[1] + 1], rx);
} else if (touchU && touchR) {
uintersect(prefUR[rx[0]], ry);
} else if (touchD && touchR) {
uintersect(prefDR[rx[0]], ry);
}
}
}
for (int x = 0; x < X; ++x) {
uintersect(suffLR[x + 1], suffLR[x]);
uintersect(suffLD[x + 1], suffLD[x]);
}
for (int x = X - 1; x >= 0; --x) {
uintersect(prefLR[x], prefLR[x + 1]);
uintersect(prefDU[x], prefDU[x + 1]);
uintersect(prefLU[x], prefLU[x + 1]);
uintersect(prefUR[x], prefUR[x + 1]);
uintersect(prefDR[x], prefDR[x + 1]);
}
for (int l = baseL[0]; l <= baseL[1]; ++l) {
for (int rotUD = 0; rotUD < 2; ++rotUD) {
auto segmU = intersect(baseU, prefLU[l + 1]);
auto segmD = intersect(baseD, suffLD[l]);
auto segmR = intersect(intersect(baseR, prefLR[l + 1]), suffLR[l]);
int d, u;
if (rotUD == 0) {
// U <= D
u = min(segmU[1], minxUD);
if (u < segmU[0]) continue;
uintersect(segmD, prefDU[u + 1]);
uintersect(segmR, prefUR[u + 1]);
if (empt(segmD)) continue;
d = segmD[1];
if (d < u) continue;
uintersect(segmR, prefDR[d + 1]);
} else {
// U >= D
d = min(segmD[1], minxUD);
if (d < segmD[0]) continue;
uintersect(segmU, prefDU[d + 1]);
uintersect(segmR, prefDR[d + 1]);
if (empt(segmU)) continue;
u = segmU[1];
if (u < d) continue;
uintersect(segmR, prefUR[u + 1]);
}
if (empt(segmR)) continue;
int r = segmR[1];
assert(in(l, segmL));
assert(in(r, segmR));
assert(in(d, segmD));
assert(in(u, segmU));
cout << L << ' ' << rv[l] << '\n';
cout << R << ' ' << rv[r] << '\n';
cout << rv[d] << ' ' << D << '\n';
cout << rv[u] << ' ' << U << '\n';
exit(0);
}
}
throw;
return 0;
}
Compilation message
In file included from /usr/include/c++/10/cassert:44,
from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
from hamburg.cpp:1:
hamburg.cpp: In function 'int32_t main()':
hamburg.cpp:276:26: error: 'segmL' was not declared in this scope; did you mean 'segmR'?
276 | assert(in(l, segmL));
| ^~~~~
