Submission #43964

# Submission time Handle Problem Language Result Execution time Memory
43964 2018-03-29T01:13:54 Z model_code Fences (JOI18_fences) C++17
100 / 100
79 ms 1280 KB
#include <cstdio>
#include <algorithm>
#include <cmath>
using namespace std;

typedef long long i64;
typedef double Double;

typedef pair<Double, Double> Pt;

const int MAXN = 200;
const int INFT = 1001001001;
const Double EPS = 1e-9;

int N, C;
int Ax[MAXN], Ay[MAXN], Bx[MAXN], By[MAXN];
Pt A[MAXN], B[MAXN];
Double cost[MAXN * 2][MAXN * 2];

bool isok(Double xa, Double ya, Double xb, Double yb, Double x, Double ylo, Double yhi)
{
	if (xb < xa) {
		swap(xa, xb);
		swap(ya, yb);
	}
	if (!(EPS < x - xa && EPS < xb - x)) return true;
	Double y = (x - xa) / (xb - xa) * (yb - ya) + ya;
	return !(EPS < y - ylo && EPS < yhi - y);
}

double triangle(Double xa, Double ya, Double xb, Double yb, Double xc, Double yc)
{
	xb -= xa; yb -= ya;
	xc -= xa; yc -= ya;
	return xb * yc - yb * xc;
}

bool cross(Pt a, Pt b, Pt c, Pt d)
{
	return
		triangle(a.first, a.second, b.first, b.second, c.first, c.second) * triangle(a.first, a.second, b.first, b.second, d.first, d.second) < 0
		&& triangle(c.first, c.second, d.first, d.second, a.first, a.second) * triangle(c.first, c.second, d.first, d.second, b.first, b.second) < 0;
}

bool isok(Pt a, Pt b)
{
	Double Cc = C;
	if (cross(a, b, { -Cc, -Cc }, { -Cc, Cc })) return false;
	if (cross(a, b, { -Cc, -Cc }, { Cc, -Cc })) return false;
	if (cross(a, b, { Cc, Cc }, { -Cc, Cc })) return false;
	if (cross(a, b, { Cc, Cc }, { Cc, -Cc })) return false;
	if (cross(a, b, { -Cc, -Cc }, { 0, Cc })) return false;
	if (cross(a, b, { Cc, -Cc }, { 0, Cc })) return false;

	if (-Cc + EPS < a.first && a.first < Cc - EPS && -Cc + EPS < a.second && a.second < Cc - EPS) return false;
	if (-Cc + EPS < b.first && b.first < Cc - EPS && -Cc + EPS < b.second && b.second < Cc - EPS) return false;

	return true;
}
bool cross(Pt a, Pt b)
{
	if (b.first < a.first) swap(a, b);
	if (!(!(EPS < a.first) && EPS < b.first)) return false;
	
	Double y = (0 - a.first) / (b.first - a.first) * (b.second - a.second) + a.second;
	return 0 < y;
}
Double check(Pt a, Pt b)
{
	if (!isok(a, b)) return INFT;

	Double dd = (b.first - a.first) * (b.first - a.first) + (b.second - a.second) * (b.second - a.second);
	return sqrt(dd);
}
Pt sd(Pt a, Pt b, Pt x)
{
	Pt aa(b.first - a.first, b.second - a.second);
	if (fabs(aa.first) < EPS && fabs(aa.second) < EPS) return a;

	Pt xa(x.first - a.first, x.second - a.second);
	Double t = (aa.first * xa.first + aa.second * xa.second) / (aa.first * aa.first + aa.second * aa.second);
	if (t < -EPS || 1 + EPS < t) return a;
	return{ a.first + aa.first * t, a.second + aa.second * t };
}

Double dd[12][12];

void apply(int s, int t, Pt a, Pt b, Pt abase, Pt bbase)
{
	Double dist = check(a, b);
	bool sgn = cross(abase, a) ^ cross(a, b) ^ cross(b, bbase);
	if (sgn) {
		dd[s * 2][t * 2 + 1] = min(dd[s * 2][t * 2 + 1], dist);
		dd[s * 2 + 1][t * 2] = dd[t * 2][s * 2 + 1] = dd[t * 2 + 1][s * 2] = dd[s * 2][t * 2 + 1];
	} else {
		dd[s * 2][t * 2] = min(dd[s * 2][t * 2], dist);
		dd[s * 2 + 1][t * 2 + 1] = dd[t * 2][s * 2] = dd[t * 2 + 1][s * 2 + 1] = dd[s * 2][t * 2];
	}
}
pair<Double, Double> compute(int u, int v)
{
	for (int i = 0; i < 12; ++i) {
		for (int j = 0; j < 12; ++j) {
			dd[i][j] = (i == j ? 0.0 : INFT);
		}
	}
	Pt corner[4] = {
		{-C, -C},
		{-C, C},
		{C, -C},
		{C, C}
	};
	apply(0, 1, A[u], A[v], A[u], A[v]);
	apply(0, 1, A[u], B[v], A[u], A[v]);
	apply(0, 1, B[u], A[v], A[u], A[v]);
	apply(0, 1, B[u], B[v], A[u], A[v]);
	apply(0, 1, A[u], sd(A[v], B[v], A[u]), A[u], A[v]);
	apply(0, 1, B[u], sd(A[v], B[v], B[u]), A[u], A[v]);
	apply(0, 1, A[v], sd(A[u], B[u], A[v]), A[v], A[u]);
	apply(0, 1, B[v], sd(A[u], B[u], B[v]), A[v], A[u]);

	for (int i = 0; i < 6; ++i) {
		for (int j = i + 1; j < 6; ++j) {
			if (i == 0 && j == 1) continue;

			if (i < 2) {
				int n = (i == 0 ? u : v);
				apply(i, j, A[n], corner[j - 2], A[n], corner[j - 2]);
				apply(i, j, B[n], corner[j - 2], A[n], corner[j - 2]);
				apply(i, j, sd(A[n], B[n], corner[j - 2]), corner[j - 2], A[n], corner[j - 2]);
			} else {
				apply(i, j, corner[i - 2], corner[j - 2], corner[i - 2], corner[j - 2]);
			}
		}
	}
	for (int i = 0; i < 12; ++i) {
		for (int j = 0; j < 12; ++j) {
			for (int k = 0; k < 12; ++k) {
				dd[j][k] = min(dd[j][k], dd[j][i] + dd[i][k]);
			}
		}
	}
	return{ dd[0][2], dd[0][3] };
}

int main()
{
	scanf("%d%d", &N, &C);
	for (int i = 0; i < N; ++i) {
		scanf("%d%d%d%d", Ax + i, Ay + i, Bx + i, By + i);
		A[i] = make_pair(Double(Ax[i]), Double(Ay[i]));
		B[i] = make_pair(Double(Bx[i]), Double(By[i]));
	}
	for (int i = 0; i < 2 * N; ++i) {
		for (int j = 0; j < 2 * N; ++j) {
			cost[i][j] = (i == j ? 0 : INFT);
		}
	}
	for (int i = 0; i < N; ++i) {
		for (int j = 0; j < N; ++j) {
			auto dist = compute(i, j);
			cost[i * 2][j * 2] = cost[i * 2 + 1][j * 2 + 1] = dist.first;
			cost[i * 2 + 1][j * 2] = cost[i * 2][j * 2 + 1] = dist.second;
		}
	}
	for (int i = 0; i < 2 * N; ++i) {
		for (int j = 0; j < 2 * N; ++j) {
			for (int k = 0; k < 2 * N; ++k) {
				cost[j][k] = min(cost[j][k], cost[j][i] + cost[i][k]);
			}
		}
	}
	Double ret = 8 * C;
	for (int i = 0; i < N; ++i) {
		ret = min(ret, cost[i * 2][i * 2 + 1]);
	}
	printf("%.3f\n", (double)ret);

	return 0;
}

Compilation message

fences.cpp: In function 'int main()':
fences.cpp:148:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &N, &C);
  ~~~~~^~~~~~~~~~~~~~~~
fences.cpp:150:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d%d", Ax + i, Ay + i, Bx + i, By + i);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 488 KB Output is correct
3 Correct 2 ms 488 KB Output is correct
4 Correct 2 ms 488 KB Output is correct
5 Correct 2 ms 488 KB Output is correct
6 Correct 2 ms 488 KB Output is correct
7 Correct 2 ms 488 KB Output is correct
8 Correct 2 ms 512 KB Output is correct
9 Correct 2 ms 512 KB Output is correct
10 Correct 2 ms 528 KB Output is correct
11 Correct 1 ms 528 KB Output is correct
12 Correct 2 ms 528 KB Output is correct
13 Correct 2 ms 528 KB Output is correct
14 Correct 2 ms 528 KB Output is correct
15 Correct 5 ms 528 KB Output is correct
16 Correct 2 ms 536 KB Output is correct
17 Correct 2 ms 536 KB Output is correct
18 Correct 2 ms 536 KB Output is correct
19 Correct 2 ms 544 KB Output is correct
20 Correct 2 ms 544 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 488 KB Output is correct
3 Correct 2 ms 488 KB Output is correct
4 Correct 2 ms 488 KB Output is correct
5 Correct 2 ms 488 KB Output is correct
6 Correct 2 ms 488 KB Output is correct
7 Correct 2 ms 488 KB Output is correct
8 Correct 2 ms 512 KB Output is correct
9 Correct 2 ms 512 KB Output is correct
10 Correct 2 ms 528 KB Output is correct
11 Correct 1 ms 528 KB Output is correct
12 Correct 2 ms 528 KB Output is correct
13 Correct 2 ms 528 KB Output is correct
14 Correct 2 ms 528 KB Output is correct
15 Correct 5 ms 528 KB Output is correct
16 Correct 2 ms 536 KB Output is correct
17 Correct 2 ms 536 KB Output is correct
18 Correct 2 ms 536 KB Output is correct
19 Correct 2 ms 544 KB Output is correct
20 Correct 2 ms 544 KB Output is correct
21 Correct 2 ms 624 KB Output is correct
22 Correct 2 ms 624 KB Output is correct
23 Correct 2 ms 624 KB Output is correct
24 Correct 2 ms 748 KB Output is correct
25 Correct 2 ms 748 KB Output is correct
26 Correct 2 ms 748 KB Output is correct
27 Correct 2 ms 748 KB Output is correct
28 Correct 2 ms 748 KB Output is correct
29 Correct 2 ms 748 KB Output is correct
30 Correct 2 ms 748 KB Output is correct
31 Correct 2 ms 748 KB Output is correct
32 Correct 2 ms 748 KB Output is correct
33 Correct 2 ms 748 KB Output is correct
34 Correct 2 ms 748 KB Output is correct
35 Correct 2 ms 748 KB Output is correct
36 Correct 2 ms 748 KB Output is correct
37 Correct 2 ms 748 KB Output is correct
38 Correct 2 ms 748 KB Output is correct
39 Correct 2 ms 748 KB Output is correct
40 Correct 2 ms 748 KB Output is correct
41 Correct 2 ms 748 KB Output is correct
42 Correct 2 ms 748 KB Output is correct
43 Correct 2 ms 748 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 488 KB Output is correct
3 Correct 2 ms 488 KB Output is correct
4 Correct 2 ms 488 KB Output is correct
5 Correct 2 ms 488 KB Output is correct
6 Correct 2 ms 488 KB Output is correct
7 Correct 2 ms 488 KB Output is correct
8 Correct 2 ms 512 KB Output is correct
9 Correct 2 ms 512 KB Output is correct
10 Correct 2 ms 528 KB Output is correct
11 Correct 1 ms 528 KB Output is correct
12 Correct 2 ms 528 KB Output is correct
13 Correct 2 ms 528 KB Output is correct
14 Correct 2 ms 528 KB Output is correct
15 Correct 5 ms 528 KB Output is correct
16 Correct 2 ms 536 KB Output is correct
17 Correct 2 ms 536 KB Output is correct
18 Correct 2 ms 536 KB Output is correct
19 Correct 2 ms 544 KB Output is correct
20 Correct 2 ms 544 KB Output is correct
21 Correct 2 ms 624 KB Output is correct
22 Correct 2 ms 624 KB Output is correct
23 Correct 2 ms 624 KB Output is correct
24 Correct 2 ms 748 KB Output is correct
25 Correct 2 ms 748 KB Output is correct
26 Correct 2 ms 748 KB Output is correct
27 Correct 2 ms 748 KB Output is correct
28 Correct 2 ms 748 KB Output is correct
29 Correct 2 ms 748 KB Output is correct
30 Correct 2 ms 748 KB Output is correct
31 Correct 2 ms 748 KB Output is correct
32 Correct 2 ms 748 KB Output is correct
33 Correct 2 ms 748 KB Output is correct
34 Correct 2 ms 748 KB Output is correct
35 Correct 2 ms 748 KB Output is correct
36 Correct 2 ms 748 KB Output is correct
37 Correct 2 ms 748 KB Output is correct
38 Correct 2 ms 748 KB Output is correct
39 Correct 2 ms 748 KB Output is correct
40 Correct 2 ms 748 KB Output is correct
41 Correct 2 ms 748 KB Output is correct
42 Correct 2 ms 748 KB Output is correct
43 Correct 2 ms 748 KB Output is correct
44 Correct 68 ms 1276 KB Output is correct
45 Correct 58 ms 1276 KB Output is correct
46 Correct 56 ms 1276 KB Output is correct
47 Correct 57 ms 1276 KB Output is correct
48 Correct 60 ms 1276 KB Output is correct
49 Correct 58 ms 1276 KB Output is correct
50 Correct 58 ms 1280 KB Output is correct
51 Correct 55 ms 1280 KB Output is correct
52 Correct 59 ms 1280 KB Output is correct
53 Correct 58 ms 1280 KB Output is correct
54 Correct 59 ms 1280 KB Output is correct
55 Correct 57 ms 1280 KB Output is correct
56 Correct 58 ms 1280 KB Output is correct
57 Correct 56 ms 1280 KB Output is correct
58 Correct 55 ms 1280 KB Output is correct
59 Correct 63 ms 1280 KB Output is correct
60 Correct 56 ms 1280 KB Output is correct
61 Correct 57 ms 1280 KB Output is correct
62 Correct 2 ms 1280 KB Output is correct
63 Correct 2 ms 1280 KB Output is correct
64 Correct 51 ms 1280 KB Output is correct
65 Correct 53 ms 1280 KB Output is correct
66 Correct 79 ms 1280 KB Output is correct
67 Correct 51 ms 1280 KB Output is correct
68 Correct 51 ms 1280 KB Output is correct
69 Correct 63 ms 1280 KB Output is correct
70 Correct 51 ms 1280 KB Output is correct
71 Correct 55 ms 1280 KB Output is correct
72 Correct 54 ms 1280 KB Output is correct