oj.uz

Submission #223847

# Submission time Handle Problem Language Result Execution time Memory
223847 2020-04-16T14:39:50 Z Minnakhmetov Hamburg Steak (JOI20_hamburg) C++14
15 / 100
 3000 ms 25608 KB 
#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define all(aaa) aaa.begin(), aaa.end()

const int N = 4e5 + 5, INF = 1e9 + 5;

struct R {
    int xl, yl, xr, yr;

    bool contains(int x, int y) const {
        return x >= xl && x <= xr && y >= yl && y <= yr;
    }
    bool intersects_hor(int y) const {
        return y >= yl && y <= yr;
    }
    bool intersects_ver(int x) const {
        return x >= xl && x <= xr;
    }
};

vector<R> rcs;
vector<int> vx, vy;
vector<pair<int, int>> ans;
pair<int, int> suf_hor[N], pref_ver[N], suf_ver[N];
int pref[N], suf[N], suf_lt[N], suf_rt[N];

pair<int, int> intersection(pair<int, int> a, pair<int, int> b) {
    return {max(a.first, b.first), min(a.second, b.second)};
}

bool solve_for_line(vector<pair<int, int>> v, int k, bool hor, int x) {
    sort(all(v));
    int last = N;
    vector<int> w;
    for (int i = (int)v.size() - 1; i >= 0; i--) {
        if (v[i].second < last) {
            if (k == 0)
                return false;
            k--;
            last = v[i].first;
            w.push_back(last);
        }
    }
    for (int y : w) {
        ans.push_back(hor ? make_pair(y, x) : make_pair(x, y));
    }
    return true;
}

vector<R> remove_covered(vector<R> v, int x, int y) {
    vector<R> nv;
    for (const R &rc : v) {
        if (!rc.contains(x, y)) {
            nv.push_back(rc);
        }
    }
    return nv;
}

bool solve(vector<R> v, int k) {
    int mn_xr = N, mx_xl = -1, mn_yr = N, mx_yl = -1;

    for (R &rc : v) {
        mn_xr = min(mn_xr, rc.xr);
        mn_yr = min(mn_yr, rc.yr);
        mx_xl = max(mx_xl, rc.xl);
        mx_yl = max(mx_yl, rc.yl);
    }

    if (mn_xr >= mx_xl && mn_yr >= mx_yl) {
        ans.push_back({mn_xr, mn_yr});
        return true;
    }
    else if (mn_xr >= mx_xl) {
        vector<pair<int, int>> sgs;
        for (R &rc : v) {
            sgs.push_back({rc.yl, rc.yr});
        }
        if (solve_for_line(sgs, k, false, mn_xr))
            return true;
        return false;
    }
    else if (mn_yr >= mx_yl) {
        vector<pair<int, int>> sgs;
        for (R &rc : v) {
            sgs.push_back({rc.xl, rc.xr});
        }
        if (solve_for_line(sgs, k, true, mn_yr))
            return true;
        return false;
    }
    else if (k == 2) {
        for (int y : {mn_yr, mx_yl}) {
            if (solve(remove_covered(v, mn_xr, y), k - 1)) {
                ans.push_back({mn_xr, y});
                return true;
            }
        }
        return false;
    }
    else if (k >= 2) {
        for (int x : {mn_xr, mx_xl}) {
            for (int y : {mn_yr, mx_yl}) {
                if (solve(remove_covered(v, x, y), k - 1)) {
                    ans.push_back({x, y});
                    return true;
                }
            }
        }
        if (k == 3)
            return false;

        if (k != 4)
            return false;

        pair<int, int> up, rt, lt, dn;
        dn = up = {1, vx.size() - 2};
        lt = rt = {1, vy.size() - 2};

        fill(suf_hor, suf_hor + N, make_pair(1, vy.size() - 2));
        fill(pref_ver, pref_ver + N, make_pair(1, vx.size() - 2));
        fill(suf_ver, suf_ver + N, make_pair(1, vx.size() - 2));
        fill(pref, pref + N, vy.size() - 2);
        fill(suf, suf + N, vy.size() - 2);
        fill(suf_lt, suf_lt + N, vx.size() - 2);
        fill(suf_rt, suf_rt + N, 1);

        for (const R &rc : v) {
            bool d = rc.intersects_hor(mn_yr),
                u = rc.intersects_hor(mx_yl),
                l = rc.intersects_ver(mn_xr),
                r = rc.intersects_ver(mx_xl);

            // cout << mn_yr << " " << rc.yl << " " << rc.yr << "\n";

            // cout << d << " " << u << " " << l << " " << r << "\n";

            int ct = d + u + l + r;
            if (ct == 1) {
                if (l)
                    lt = intersection(lt, {rc.yl, rc.yr});
                else if (r)
                    rt = intersection(rt, {rc.yl, rc.yr});
                else if (u)
                    up = intersection(up, {rc.xl, rc.xr});
                else
                    dn = intersection(dn, {rc.xl, rc.xr});
            }
            else if (ct == 2) {
                if (l && r) {
                    suf_hor[rc.yl] = intersection(suf_hor[rc.yl], 
                        make_pair(rc.yl, rc.yr));
                }
                else if (d && l) {
                    pref[rc.xr] = min(pref[rc.xr], rc.yr);
                }
                else if (d && r) {
                    suf[rc.xl] = min(suf[rc.xl], rc.yr);
                }
                else if (l && u) {
                    suf_lt[rc.yl] = min(rc.xr, suf_lt[rc.yl]);
                }
                else if (r && u) {
                    suf_rt[rc.yl] = max(rc.xl, suf_rt[rc.yl]);
                }
                else {
                    pref_ver[rc.xr] = intersection(pref_ver[rc.xr], {rc.xl, rc.xr});
                    suf_ver[rc.xl] = intersection(suf_ver[rc.xl], {rc.xl, rc.xr});
                }
            }

            for (int i = N - 2; i >= 0; i--) {
                suf_hor[i] = intersection(suf_hor[i], suf_hor[i + 1]);
                suf_lt[i] = min(suf_lt[i], suf_lt[i + 1]);
                suf_rt[i] = max(suf_rt[i], suf_rt[i + 1]);
                suf_ver[i] = intersection(suf_ver[i], suf_ver[i + 1]);
                suf[i] = min(suf[i], suf[i + 1]);
            }

            for (int i = 1; i < N; i++) {
                pref_ver[i] = intersection(pref_ver[i], pref_ver[i - 1]);
                pref[i] = min(pref[i], pref[i - 1]);
            }
        }

        for (int i = dn.first; i <= dn.second; i++) {
            int mx_lt = pref[i - 1],
                mx_rt = suf[i + 1];

            pair<int, int> nup = intersection(up, 
                intersection(pref_ver[i - 1], suf_ver[i + 1]));

            if (nup.first > nup.second) {
                continue;
            }

            int y_lt = min(mx_lt, suf_hor[0].second);
            y_lt = min(y_lt, lt.second);
            if (y_lt < lt.first) {
                continue;
            }

            pair<int, int> nrt = intersection(rt, suf_hor[y_lt + 1]);
            if (nrt.first > nrt.second) {
                continue;
            }

            int y_rt = nrt.second;

            nup = intersection(nup, make_pair(suf_rt[y_rt + 1], suf_lt[y_lt + 1]));

            if (nup.first > nup.second) {
                continue;
            }

            ans.push_back({i, mn_yr});
            ans.push_back({mn_xr, y_lt});
            ans.push_back({mx_xl, y_rt});
            ans.push_back({nup.first, mx_yl});

            return true;
        }

        for (int i = dn.first; i <= dn.second; i++) {
            int mx_lt = pref[i - 1],
                mx_rt = suf[i + 1];

            pair<int, int> nup = intersection(up, 
                intersection(pref_ver[i - 1], suf_ver[i + 1]));

            if (nup.first > nup.second) {
                continue;
            }

            int y_rt = min(mx_rt, suf_hor[0].second);
            y_rt = min(y_rt, lt.second);
            if (y_rt < lt.first) {
                continue;
            }

            pair<int, int> nlt = intersection(lt, suf_hor[y_rt + 1]);
            if (nlt.first > nlt.second) {
                continue;
            }

            int y_lt = nlt.second;

            nup = intersection(nup, make_pair(suf_rt[y_rt + 1], suf_lt[y_lt + 1]));

            if (nup.first > nup.second) {
                continue;
            }

            ans.push_back({i, mn_yr});
            ans.push_back({mn_xr, y_lt});
            ans.push_back({mx_xl, y_rt});
            ans.push_back({nup.first, mx_yl});

            return true;
        }
    }
    return false;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int n, k;
    cin >> n >> k;

    for (int i = 0; i < n; i++) {
        R r;
        cin >> r.xl >> r.yl >> r.xr >> r.yr;
        vx.push_back(r.xl);
        vx.push_back(r.xr);
        vy.push_back(r.yl);
        vy.push_back(r.yr);
        rcs.push_back(r);
    }

    vx.push_back(-1);
    vx.push_back(INF);

    vy.push_back(-1);
    vy.push_back(INF);

    sort(all(vx));
    vx.erase(unique(all(vx)), vx.end());
    sort(all(vy));
    vy.erase(unique(all(vy)), vy.end());

    for (int i = 0; i < n; i++) {
        rcs[i].xl = lower_bound(all(vx), rcs[i].xl) - vx.begin();
        rcs[i].xr = lower_bound(all(vx), rcs[i].xr) - vx.begin();
        rcs[i].yl = lower_bound(all(vy), rcs[i].yl) - vy.begin();
        rcs[i].yr = lower_bound(all(vy), rcs[i].yr) - vy.begin();
    }

    solve(rcs, k);

    while (ans.size() < k)
        ans.push_back({0, 0});

    for (auto p : ans) {
        cout << vx[p.first] << " " << vy[p.second] << "\n";
    }

    return 0;
}

Compilation message

hamburg.cpp: In function 'bool solve(std::vector<R>, int)':
hamburg.cpp:190:17: warning: unused variable 'mx_rt' [-Wunused-variable]
  190 |                 mx_rt = suf[i + 1];
      |                 ^~~~~
hamburg.cpp:227:17: warning: unused variable 'mx_lt' [-Wunused-variable]
  227 |             int mx_lt = pref[i - 1],
      |                 ^~~~~
hamburg.cpp: In function 'int main()':
hamburg.cpp:304:23: warning: comparison of integer expressions of different signedness: 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  304 |     while (ans.size() < k)
      |            ~~~~~~~~~~~^~~

Subtask #1
1.0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 512 KB Output is correct
2 Correct 3 ms 416 KB Output is correct
3 Correct 3 ms 512 KB Output is correct
4 Correct 3 ms 512 KB Output is correct

Subtask #2
1.0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 512 KB Output is correct
2 Correct 3 ms 512 KB Output is correct
3 Correct 3 ms 512 KB Output is correct
4 Correct 3 ms 512 KB Output is correct

Subtask #3
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 512 KB Output is correct
2 Correct 3 ms 512 KB Output is correct
3 Correct 3 ms 512 KB Output is correct
4 Correct 3 ms 512 KB Output is correct
5 Correct 3 ms 512 KB Output is correct
6 Correct 3 ms 512 KB Output is correct
7 Correct 3 ms 512 KB Output is correct
8 Correct 3 ms 512 KB Output is correct
9 Correct 4 ms 640 KB Output is correct
10 Correct 3 ms 512 KB Output is correct
11 Correct 3 ms 512 KB Output is correct
12 Correct 3 ms 512 KB Output is correct

Subtask #4
0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 512 KB Output is correct
2 Correct 3 ms 512 KB Output is correct
3 Correct 4 ms 512 KB Output is correct
4 Correct 4 ms 512 KB Output is correct
5 Correct 3 ms 512 KB Output is correct
6 Correct 3 ms 512 KB Output is correct
7 Correct 4 ms 512 KB Output is correct
8 Correct 4 ms 512 KB Output is correct
9 Correct 3 ms 512 KB Output is correct
10 Correct 3 ms 512 KB Output is correct
11 Correct 3 ms 512 KB Output is correct
12 Correct 3 ms 512 KB Output is correct
13 Correct 4 ms 640 KB Output is correct
14 Execution timed out 3093 ms 16216 KB Time limit exceeded
15 Halted 0 ms 0 KB -

Subtask #5
1.0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 512 KB Output is correct
2 Correct 3 ms 416 KB Output is correct
3 Correct 3 ms 512 KB Output is correct
4 Correct 3 ms 512 KB Output is correct
5 Correct 316 ms 10004 KB Output is correct
6 Correct 371 ms 10000 KB Output is correct
7 Correct 325 ms 10056 KB Output is correct
8 Correct 342 ms 9960 KB Output is correct

Subtask #6
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 512 KB Output is correct
2 Correct 3 ms 512 KB Output is correct
3 Correct 3 ms 512 KB Output is correct
4 Correct 3 ms 512 KB Output is correct
5 Correct 342 ms 16156 KB Output is correct
6 Correct 361 ms 15976 KB Output is correct
7 Correct 346 ms 16036 KB Output is correct
8 Correct 346 ms 19012 KB Output is correct

Subtask #7
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 512 KB Output is correct
2 Correct 3 ms 512 KB Output is correct
3 Correct 3 ms 512 KB Output is correct
4 Correct 3 ms 512 KB Output is correct
5 Correct 3 ms 512 KB Output is correct
6 Correct 3 ms 512 KB Output is correct
7 Correct 3 ms 512 KB Output is correct
8 Correct 3 ms 512 KB Output is correct
9 Correct 4 ms 640 KB Output is correct
10 Correct 3 ms 512 KB Output is correct
11 Correct 3 ms 512 KB Output is correct
12 Correct 3 ms 512 KB Output is correct
13 Correct 357 ms 13376 KB Output is correct
14 Correct 364 ms 13336 KB Output is correct
15 Correct 367 ms 13384 KB Output is correct
16 Correct 388 ms 13336 KB Output is correct
17 Correct 365 ms 13424 KB Output is correct
18 Correct 350 ms 13384 KB Output is correct
19 Correct 345 ms 18244 KB Output is correct
20 Correct 334 ms 19652 KB Output is correct
21 Correct 407 ms 25608 KB Output is correct
22 Correct 362 ms 19880 KB Output is correct
23 Correct 375 ms 23576 KB Output is correct
24 Correct 378 ms 24804 KB Output is correct

Subtask #8
0 / 79.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 512 KB Output is correct
2 Correct 3 ms 512 KB Output is correct
3 Correct 4 ms 512 KB Output is correct
4 Correct 4 ms 512 KB Output is correct
5 Correct 3 ms 512 KB Output is correct
6 Correct 3 ms 512 KB Output is correct
7 Correct 4 ms 512 KB Output is correct
8 Correct 4 ms 512 KB Output is correct
9 Correct 3 ms 512 KB Output is correct
10 Correct 3 ms 512 KB Output is correct
11 Correct 3 ms 512 KB Output is correct
12 Correct 3 ms 512 KB Output is correct
13 Correct 4 ms 640 KB Output is correct
14 Execution timed out 3093 ms 16216 KB Time limit exceeded
15 Halted 0 ms 0 KB -