Submission #414575

#	Time	Username	Problem	Language	Result	Execution time	Memory
414575		usachevd0	Hamburg Steak (JOI20_hamburg)	C++17	100 / 100	704 ms	66184 KiB

hamburg

#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];
            cout << rv[L] << ' ' << rv[l] << '\n';
            cout << rv[R] << ' ' << rv[r] << '\n';
            cout << rv[d] << ' ' << rv[D] << '\n';
            cout << rv[u] << ' ' << rv[U] << '\n';
            exit(0);
        }
    }
    throw;
    
    return 0;
}

• Subtask 1: 1 / 1
• Subtask 2: 1 / 1
• Subtask 3: 3 / 3
• Subtask 4: 6 / 6
• Subtask 5: 1 / 1
• Subtask 6: 3 / 3
• Subtask 7: 6 / 6
• Subtask 8: 79 / 79