oj.uz

Submission #892817

# Submission time Handle Problem Language Result Execution time Memory
892817 2023-12-26T03:20:53 Z box Fences (JOI18_fences) C++17
100 / 100
 12 ms 1060 KB 
#include <bits/stdc++.h>
using namespace std;

#define ar array
#define sz(v) int(std::size(v))
using i64 = long long;
using T = double;

const T eps = 1e-7;

struct point { T x, y; };
point operator+(const point a, const point b) { return {a.x + b.x, a.y + b.y}; }
point operator-(const point a, const point b) { return {a.x - b.x, a.y - b.y}; }
point operator*(const point a, const T v) { return {a.x * v, a.y * v}; }
T dot(const point a, const point b) { return a.x * b.x + a.y * b.y; }
T len(const point a) { return sqrt(a.x * a.x + a.y * a.y); }
T cross(const point a, const point b) { return a.x * b.y - a.y * b.x; }
bool cw(const point a, const point b, const point c) { return cross(b - a, c - a) > 0; }
bool ccw(const point a, const point b, const point c) { return cross(b - a, c - a) < 0; }

struct line { point a, b; };
bool isect(line p, line q, bool touch) {
    for (int rep = 0; rep < 2; rep++) {
        bool f = 0;
        f |= cw(p.a, p.b, q.a) && ccw(p.a, p.b, q.b);
        f |= ccw(p.a, p.b, q.a) && cw(p.a, p.b, q.b);
        if (touch) {
            f |= cw(p.a, p.b, q.a) && !cw(p.a, p.b, q.b);
            f |= !cw(p.a, p.b, q.a) && cw(p.a, p.b, q.b);
        }
        if (!f) return 0;
        swap(p, q);
    }
    return 1;
}
point proj(const line p, const point a) {
    point v = p.b - p.a, u = a - p.a;
    T ratio = dot(u, v) / dot(v, v);
    if (ratio < 0 || ratio > 1 || dot(v, v) == 0)
        return len(p.a - a) < len(p.b - a) ? p.a : p.b;
    return p.a + v * ratio;
}

const line half{point{T(0), T(0)}, point{T(1), T{401}}};

int n, s;
vector<line> lines;
line diag1, diag2;

bool good(const line l) {
    return !isect(l, diag1, 0) && !isect(l, diag2, 0);
}

void ckmin(T &a, T b) {
    a = min(a, b);
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n >> s;
    lines.resize(n);
    for (auto &[p, q] : lines) {
        int a, b, c, d;
        cin >> a >> b >> c >> d;
        p = point{T(a), T(b)};
        q = point{T(c), T(d)};
    }
    diag1 = line{point{T(-s), T(-s)}, point{T(s), T(s)}};
    diag2 = line{point{T(s), T(-s)}, point{T(-s), T(s)}};
    for (int x : {-s, s}) for (int y : {-s, s}) {
        point p{T(x), T(y)};
        lines.push_back({p, p});
    }
    vector<line> tmp;
    for (line l : lines) {
        if (!isect(l, half, 1)) tmp.push_back(l);
        else {
            point v = l.b - l.a;
            T low = 0, hi = 1;
            for (int it = 0; it < 35; it++) {
                T m = (low + hi) / 2;
                isect(line{l.a, l.a + v * m}, half, 1) ? hi = m : low = m;
            }
            T m = (low + hi) / 2;
            tmp.push_back(line{l.a, l.a + v * (m - eps)});
            tmp.push_back(line{l.a + v * (m + eps), l.b});
        }
    }
    swap(tmp, lines);
    n = sz(lines);
    const T inf = s * 8;
    vector dist(n * 2, vector<T>(n * 2, inf));
    for (int i = 0; i < sz(lines); i++) {
        for (int j = i + 1; j < sz(lines); j++) {
            auto add = [&](const line l) {
                if (good(l)) {
                    T d = len(l.b - l.a);
                    bool t = isect(l, half, 1);
                    if (t) {
                        ckmin(dist[i][j + n], d);
                        ckmin(dist[i + n][j], d);
                        ckmin(dist[j][i + n], d);
                        ckmin(dist[j + n][i], d);
                    } else {
                        ckmin(dist[i][j], d);
                        ckmin(dist[i + n][j + n], d);
                        ckmin(dist[j + n][i + n], d);
                        ckmin(dist[j][i], d);
                    }
                }
            };
            add(line{lines[i].a, lines[j].a});
            add(line{lines[i].a, lines[j].b});
            add(line{lines[i].b, lines[j].a});
            add(line{lines[i].b, lines[j].b});
            add(line{lines[i].a, proj(lines[j], lines[i].a)});
            add(line{lines[i].b, proj(lines[j], lines[i].b)});
            add(line{lines[j].a, proj(lines[i], lines[j].a)});
            add(line{lines[j].b, proj(lines[i], lines[j].b)});
        }
    }
    for (int k = 0; k < n * 2; k++) for (int i = 0; i < n * 2; i++) for (int j = 0; j < n * 2; j++)
        ckmin(dist[i][j], dist[i][k] + dist[k][j]);
    T ans = inf;
    for (int i = 0; i < n; i++) ckmin(ans, dist[i][i + n]);
    cout << fixed << setprecision(8) << ans << '\n';
}

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 344 KB Output is correct
6 Correct 1 ms 344 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 344 KB Output is correct
16 Correct 0 ms 344 KB Output is correct
17 Correct 1 ms 344 KB Output is correct
18 Correct 0 ms 600 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct

Subtask #2
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 344 KB Output is correct
6 Correct 1 ms 344 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 344 KB Output is correct
16 Correct 0 ms 344 KB Output is correct
17 Correct 1 ms 344 KB Output is correct
18 Correct 0 ms 600 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 0 ms 348 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 0 ms 348 KB Output is correct
26 Correct 0 ms 348 KB Output is correct
27 Correct 0 ms 348 KB Output is correct
28 Correct 0 ms 348 KB Output is correct
29 Correct 0 ms 348 KB Output is correct
30 Correct 1 ms 348 KB Output is correct
31 Correct 0 ms 348 KB Output is correct
32 Correct 0 ms 348 KB Output is correct
33 Correct 0 ms 348 KB Output is correct
34 Correct 0 ms 348 KB Output is correct
35 Correct 0 ms 348 KB Output is correct
36 Correct 0 ms 348 KB Output is correct
37 Correct 0 ms 348 KB Output is correct
38 Correct 0 ms 348 KB Output is correct
39 Correct 0 ms 348 KB Output is correct
40 Correct 1 ms 348 KB Output is correct
41 Correct 0 ms 348 KB Output is correct
42 Correct 0 ms 348 KB Output is correct
43 Correct 0 ms 348 KB Output is correct

Subtask #3
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 344 KB Output is correct
6 Correct 1 ms 344 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 344 KB Output is correct
16 Correct 0 ms 344 KB Output is correct
17 Correct 1 ms 344 KB Output is correct
18 Correct 0 ms 600 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 0 ms 348 KB Output is correct
24 Correct 0 ms 348 KB Output is correct
25 Correct 0 ms 348 KB Output is correct
26 Correct 0 ms 348 KB Output is correct
27 Correct 0 ms 348 KB Output is correct
28 Correct 0 ms 348 KB Output is correct
29 Correct 0 ms 348 KB Output is correct
30 Correct 1 ms 348 KB Output is correct
31 Correct 0 ms 348 KB Output is correct
32 Correct 0 ms 348 KB Output is correct
33 Correct 0 ms 348 KB Output is correct
34 Correct 0 ms 348 KB Output is correct
35 Correct 0 ms 348 KB Output is correct
36 Correct 0 ms 348 KB Output is correct
37 Correct 0 ms 348 KB Output is correct
38 Correct 0 ms 348 KB Output is correct
39 Correct 0 ms 348 KB Output is correct
40 Correct 1 ms 348 KB Output is correct
41 Correct 0 ms 348 KB Output is correct
42 Correct 0 ms 348 KB Output is correct
43 Correct 0 ms 348 KB Output is correct
44 Correct 10 ms 860 KB Output is correct
45 Correct 9 ms 604 KB Output is correct
46 Correct 9 ms 860 KB Output is correct
47 Correct 10 ms 860 KB Output is correct
48 Correct 11 ms 1060 KB Output is correct
49 Correct 11 ms 924 KB Output is correct
50 Correct 9 ms 856 KB Output is correct
51 Correct 8 ms 604 KB Output is correct
52 Correct 9 ms 868 KB Output is correct
53 Correct 10 ms 860 KB Output is correct
54 Correct 9 ms 852 KB Output is correct
55 Correct 12 ms 860 KB Output is correct
56 Correct 12 ms 860 KB Output is correct
57 Correct 8 ms 604 KB Output is correct
58 Correct 10 ms 884 KB Output is correct
59 Correct 9 ms 872 KB Output is correct
60 Correct 11 ms 860 KB Output is correct
61 Correct 12 ms 860 KB Output is correct
62 Correct 0 ms 348 KB Output is correct
63 Correct 0 ms 348 KB Output is correct
64 Correct 7 ms 804 KB Output is correct
65 Correct 7 ms 604 KB Output is correct
66 Correct 9 ms 604 KB Output is correct
67 Correct 10 ms 860 KB Output is correct
68 Correct 11 ms 860 KB Output is correct
69 Correct 8 ms 604 KB Output is correct
70 Correct 6 ms 776 KB Output is correct
71 Correct 8 ms 600 KB Output is correct
72 Correct 7 ms 600 KB Output is correct