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Submission #421800

# Submission time Handle Problem Language Result Execution time Memory
421800 2021-06-09T12:18:07 Z palilo None (KOI16_laser) C++17
100 / 100
 195 ms 18284 KB 
#include <bits/stdc++.h>
using namespace std;

namespace std {
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0200r0.html
template <class Fun>
class y_combinator_result {
    Fun fun_;

public:
    template <class T>
    explicit y_combinator_result(T&& fun) : fun_(std::forward<T>(fun)) {}

    template <class... Args>
    decltype(auto) operator()(Args&&... args) {
        return fun_(std::ref(*this), std::forward<Args>(args)...);
    }
};

template <class Fun>
decltype(auto) y_combinator(Fun&& fun) {
    return y_combinator_result<std::decay_t<Fun>>(std::forward<Fun>(fun));
}
}; // namespace std

struct point {
    int x, y, id;
    point() = default;
    point(int _x, int _y, int _id) : x(_x), y(_y), id(_id) {}

    using P = point;

    bool operator<(const P& p) const { return tie(x, y) < tie(p.x, p.y); }
    bool operator==(const P& p) const { return id == p.id; }

    int64_t cross(const P& a, const P& b) const { return int64_t(a.x - x) * (b.y - y) - int64_t(a.y - y) * (b.x - x); }
};

vector<point> convex_hull(vector<point> pts) {
    sort(pts.begin(), pts.end());
    vector<point> hull(pts.size() + 1);
    int s = 0, t = 0;
    for (int it = 2; it--; s = --t, reverse(pts.begin(), pts.end()))
        for (const auto& p : pts) {
            while (t >= s + 2 && hull[t - 2].cross(hull[t - 1], p) <= 0) t--;
            hull[t++] = p;
        }
    return {hull.begin(), hull.begin() + t - (t == 2 && hull[0] == hull[1])};
}

int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
#ifdef palilo
    freopen("in", "r", stdin);
    freopen("out", "w", stdout);
#endif

    int n;
    cin >> n;

    vector<point> a(3 * n);
    for (int i = 0; i < n; ++i)
        cin >> a[i].x >> a[i].y, a[i].id = ~i;
    for (int i = n; i < 3 * n; ++i)
        cin >> a[i].x >> a[i].y, a[i].id = i - n;

    vector<pair<int, int>> ans(n);
    y_combinator([&](auto self, auto st, auto ed) -> void {
        if (st == ed) return;
        if (ed - st == 3) {
            swap(*st, *find_if(st, ed, [&](const auto& x) { return x.id < 0; }));
            ans[~st->id] = {(st + 1)->id, (st + 2)->id};
            return;
        }

        auto hull = convex_hull({st, ed});
        point pivot;
        bool is_blue; // pivot is blue?
        if (auto it = find_if(hull.begin(), hull.end(), [&](const auto& x) { return x.id < 0; }); it == hull.end())
            pivot = hull.front(), is_blue = false;
        else
            pivot = *it, is_blue = true;

        swap(*st, *find(st, ed, pivot));
        sort(st + 1, ed, [&](const auto& lhs, const auto& rhs) {
            return st->cross(lhs, rhs) > 0;
        });

        int sum = 0;
        if (is_blue) {
            vector<point>::iterator r;
            for (auto it = st; it != ed; ++it) {
                if (it->id < 0) sum += 2;
                else {
                    --sum;
                    if (sum == 1) r = prev(it);
                    if (sum == 0) {
                        swap(*st, *r);
                        self(st, r), self(r, it + 1), self(it + 1, ed);
                        return;
                    }
                }
            }
        } else {
            for (auto it = st; it != ed - 1; ++it) {
                sum += it->id < 0 ? 2 : -1;
                if (sum == 0) {
                    self(st, it + 1), self(it + 1, ed);
                    return;
                }
            }
            sum = -1;
            for (auto it = ed - 1; it != st; --it) {
                sum += it->id < 0 ? 2 : -1;
                if (sum == 0) {
                    swap(*st, *prev(it));
                    self(st, it - 1), self(it - 1, ed);
                    return;
                }
            }
        }
        assert(false);
    })(a.begin(), a.end());

    for (const auto& [i, j] : ans)
        cout << i + 1 << ' ' << j + 1 << '\n';
}

Subtask #1
14.0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 312 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 308 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 1 ms 308 KB Output is correct
14 Correct 1 ms 204 KB Output is correct
15 Correct 1 ms 204 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
17 Correct 1 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct
19 Correct 1 ms 204 KB Output is correct
20 Correct 1 ms 204 KB Output is correct
21 Correct 1 ms 204 KB Output is correct
22 Correct 1 ms 204 KB Output is correct
23 Correct 1 ms 304 KB Output is correct
24 Correct 0 ms 204 KB Output is correct

Subtask #2
19.0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 1 ms 308 KB Output is correct
11 Correct 1 ms 460 KB Output is correct
12 Correct 1 ms 460 KB Output is correct
13 Correct 1 ms 460 KB Output is correct
14 Correct 1 ms 460 KB Output is correct

Subtask #3
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 312 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 308 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 1 ms 308 KB Output is correct
14 Correct 1 ms 204 KB Output is correct
15 Correct 1 ms 204 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
17 Correct 1 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct
19 Correct 1 ms 204 KB Output is correct
20 Correct 1 ms 204 KB Output is correct
21 Correct 1 ms 204 KB Output is correct
22 Correct 1 ms 204 KB Output is correct
23 Correct 1 ms 304 KB Output is correct
24 Correct 0 ms 204 KB Output is correct
25 Correct 1 ms 332 KB Output is correct
26 Correct 1 ms 332 KB Output is correct
27 Correct 1 ms 332 KB Output is correct
28 Correct 1 ms 332 KB Output is correct
29 Correct 1 ms 332 KB Output is correct
30 Correct 1 ms 332 KB Output is correct
31 Correct 1 ms 332 KB Output is correct
32 Correct 1 ms 332 KB Output is correct
33 Correct 1 ms 332 KB Output is correct
34 Correct 1 ms 308 KB Output is correct
35 Correct 1 ms 460 KB Output is correct
36 Correct 1 ms 460 KB Output is correct
37 Correct 1 ms 460 KB Output is correct
38 Correct 1 ms 460 KB Output is correct
39 Correct 1 ms 332 KB Output is correct
40 Correct 2 ms 320 KB Output is correct
41 Correct 1 ms 332 KB Output is correct
42 Correct 1 ms 332 KB Output is correct
43 Correct 1 ms 332 KB Output is correct
44 Correct 1 ms 332 KB Output is correct
45 Correct 1 ms 332 KB Output is correct
46 Correct 1 ms 332 KB Output is correct
47 Correct 1 ms 332 KB Output is correct
48 Correct 1 ms 332 KB Output is correct
49 Correct 2 ms 460 KB Output is correct
50 Correct 2 ms 460 KB Output is correct
51 Correct 2 ms 460 KB Output is correct
52 Correct 2 ms 460 KB Output is correct
53 Correct 2 ms 440 KB Output is correct
54 Correct 2 ms 460 KB Output is correct
55 Correct 2 ms 444 KB Output is correct
56 Correct 2 ms 460 KB Output is correct
57 Correct 2 ms 332 KB Output is correct
58 Correct 1 ms 332 KB Output is correct
59 Correct 2 ms 332 KB Output is correct
60 Correct 1 ms 332 KB Output is correct
61 Correct 1 ms 332 KB Output is correct
62 Correct 1 ms 332 KB Output is correct
63 Correct 1 ms 332 KB Output is correct
64 Correct 1 ms 332 KB Output is correct
65 Correct 1 ms 332 KB Output is correct
66 Correct 1 ms 332 KB Output is correct
67 Correct 1 ms 332 KB Output is correct
68 Correct 1 ms 332 KB Output is correct

Subtask #4
34.0 / 34.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 312 KB Output is correct
6 Correct 1 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 308 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 1 ms 308 KB Output is correct
14 Correct 1 ms 204 KB Output is correct
15 Correct 1 ms 204 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
17 Correct 1 ms 204 KB Output is correct
18 Correct 1 ms 204 KB Output is correct
19 Correct 1 ms 204 KB Output is correct
20 Correct 1 ms 204 KB Output is correct
21 Correct 1 ms 204 KB Output is correct
22 Correct 1 ms 204 KB Output is correct
23 Correct 1 ms 304 KB Output is correct
24 Correct 0 ms 204 KB Output is correct
25 Correct 1 ms 332 KB Output is correct
26 Correct 1 ms 332 KB Output is correct
27 Correct 1 ms 332 KB Output is correct
28 Correct 1 ms 332 KB Output is correct
29 Correct 1 ms 332 KB Output is correct
30 Correct 1 ms 332 KB Output is correct
31 Correct 1 ms 332 KB Output is correct
32 Correct 1 ms 332 KB Output is correct
33 Correct 1 ms 332 KB Output is correct
34 Correct 1 ms 308 KB Output is correct
35 Correct 1 ms 460 KB Output is correct
36 Correct 1 ms 460 KB Output is correct
37 Correct 1 ms 460 KB Output is correct
38 Correct 1 ms 460 KB Output is correct
39 Correct 1 ms 332 KB Output is correct
40 Correct 2 ms 320 KB Output is correct
41 Correct 1 ms 332 KB Output is correct
42 Correct 1 ms 332 KB Output is correct
43 Correct 1 ms 332 KB Output is correct
44 Correct 1 ms 332 KB Output is correct
45 Correct 1 ms 332 KB Output is correct
46 Correct 1 ms 332 KB Output is correct
47 Correct 1 ms 332 KB Output is correct
48 Correct 1 ms 332 KB Output is correct
49 Correct 2 ms 460 KB Output is correct
50 Correct 2 ms 460 KB Output is correct
51 Correct 2 ms 460 KB Output is correct
52 Correct 2 ms 460 KB Output is correct
53 Correct 2 ms 440 KB Output is correct
54 Correct 2 ms 460 KB Output is correct
55 Correct 2 ms 444 KB Output is correct
56 Correct 2 ms 460 KB Output is correct
57 Correct 2 ms 332 KB Output is correct
58 Correct 1 ms 332 KB Output is correct
59 Correct 2 ms 332 KB Output is correct
60 Correct 1 ms 332 KB Output is correct
61 Correct 1 ms 332 KB Output is correct
62 Correct 1 ms 332 KB Output is correct
63 Correct 1 ms 332 KB Output is correct
64 Correct 1 ms 332 KB Output is correct
65 Correct 1 ms 332 KB Output is correct
66 Correct 1 ms 332 KB Output is correct
67 Correct 1 ms 332 KB Output is correct
68 Correct 1 ms 332 KB Output is correct
69 Correct 20 ms 520 KB Output is correct
70 Correct 20 ms 460 KB Output is correct
71 Correct 20 ms 460 KB Output is correct
72 Correct 13 ms 504 KB Output is correct
73 Correct 12 ms 508 KB Output is correct
74 Correct 20 ms 460 KB Output is correct
75 Correct 19 ms 460 KB Output is correct
76 Correct 22 ms 460 KB Output is correct
77 Correct 24 ms 516 KB Output is correct
78 Correct 22 ms 460 KB Output is correct
79 Correct 127 ms 18244 KB Output is correct
80 Correct 136 ms 18140 KB Output is correct
81 Correct 131 ms 18116 KB Output is correct
82 Correct 131 ms 18124 KB Output is correct
83 Correct 116 ms 18192 KB Output is correct
84 Correct 118 ms 18236 KB Output is correct
85 Correct 115 ms 18200 KB Output is correct
86 Correct 115 ms 18284 KB Output is correct
87 Correct 195 ms 848 KB Output is correct
88 Correct 187 ms 832 KB Output is correct
89 Correct 187 ms 868 KB Output is correct
90 Correct 186 ms 836 KB Output is correct
91 Correct 41 ms 496 KB Output is correct
92 Correct 43 ms 552 KB Output is correct
93 Correct 32 ms 456 KB Output is correct
94 Correct 17 ms 524 KB Output is correct
95 Correct 19 ms 460 KB Output is correct
96 Correct 22 ms 560 KB Output is correct
97 Correct 20 ms 528 KB Output is correct
98 Correct 19 ms 460 KB Output is correct