oj.uz

Submission #132015

# Submission time Handle Problem Language Result Execution time Memory
132015 2019-07-18T07:55:53 Z 이온조(#3189) Fences (JOI18_fences) C++14
51 / 100
 386 ms 24312 KB 
#pragma GCC optimize ("Ofast")
#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
using pid = pair<int, double>;
using pdi = pair<double, int>;
using pdd = pair<double, double>;
#define X first
#define Y second

const double eps = 1e-6;

struct line { pdd S, E; };
struct dot { pdd D; int id; bool ps; };
struct node { double v; int c, id; };

bool operator <(node PP, node QQ) { return PP.v > QQ.v; }

inline double f(double x) { return max(x, -x); }
inline double dst(pdd A, pdd B) { return sqrt((A.X-B.X) * (A.X-B.X) + (A.Y-B.Y) * (A.Y-B.Y)); }
inline double CCW(pdd A, pdd B, pdd C) { return A.X*B.Y + B.X*C.Y + C.X*A.Y - A.Y*B.X - B.Y*C.X - C.Y*A.X; }
inline int CCWs(pdd A, pdd B, pdd C) {
	int tmp = CCW(A, B, C);
	if(tmp < 0) return -1;
	if(tmp > 0) return +1;
	if(tmp == 0) return 0;
}
inline bool on(line A, pdd B) {
	if(A.S > A.E) swap(A.S, A.E);
	if(B < A.S || A.E < B) return false;
	return f(CCW(A.S, A.E, B)) < eps;
}
inline bool its(line A, line B) { // strict
	if(on(A, B.S) || on(A, B.E) || on(B, A.S) || on(B, A.E)) return false;
	return CCWs(A.S, A.E, B.S) * CCWs(A.S, A.E, B.E) == -1 && CCWs(B.S, B.E, A.S) * CCWs(B.S, B.E, A.E) == -1;
}
inline pdd push(line A, pdd B) {
	double ds = dst(A.S, A.E);
	double d = f(CCW(A.S, A.E, B) / ds);
	double dx = A.S.Y - A.E.Y, dy = A.E.X - A.S.X;
	pdd PA = {B.X + dx * (d/ds), B.Y + dy * (d/ds)};
	pdd PB = {B.X - dx * (d/ds), B.Y - dy * (d/ds)};
	if(dst(PA, A.S) > dst(PB, A.S)) swap(PA, PB);
	return PA;
}

line I = {{0.0, 0.0}, {1000.0, 1.0}};
vector<dot> T;
vector<pid> adj[1000009];
line A[111];
int N, S, K;
double ans = 1e9, D[2][1000009];

inline bool ok(line L) {
	bool f = 0;
	f |= its(L, {{S, S}, {S, -S}});
	f |= its(L, {{S, -S}, {-S, -S}});
	f |= its(L, {{-S, -S}, {-S, S}});
	f |= its(L, {{-S, S}, {S, S}});
	f |= its(L, {{S, S}, {-S, -S}});
	f |= its(L, {{-S, S}, {S, -S}});
	return !f;
}

void dijk(int st) {
	// printf("start: (%d, %d)\n", T[st].D.X, T[st].D.Y);
	for(int i=0; i<K; i++) D[0][i] = D[1][i] = 1e9;
	D[0][st] = 0.0;
	priority_queue<node> pq; pq.push({0.0, 0, st});
	while(pq.size()) {
		node n = pq.top(); pq.pop();
		if(n.id == st && n.c == 1) break;
		// printf("now: (%f, %d, (%d, %d))\n", n.v, n.c, T[n.id].D.X, T[n.id].D.Y);
		if(f(D[n.c][n.id] - n.v) > eps || n.v > ans) continue;
		for(auto& it: adj[n.id]) {
			int tc = n.c;
			if(its({T[n.id].D, T[it.X].D}, I)) tc = 1 - tc;
			if(D[tc][it.X] > n.v + it.Y) {
				D[tc][it.X] = n.v + it.Y;
				pq.push({D[tc][it.X], tc, it.X});
			}
		}
	}
	ans = min(ans, D[1][st]);
}

void make_edge(int u, int v, double c) {
	adj[u].push_back({v, c});
	adj[v].push_back({u, c});
}

int main() {
	scanf("%d%d",&N,&S);
	// N = 100; S = 100;
	ans = 8.0*S;
	for(int i=1; i<=N; i++) {
		scanf("%lf%lf%lf%lf", &A[i].S.X, &A[i].S.Y, &A[i].E.X, &A[i].E.Y);
		// A[i].S = {i, 100}; A[i].E = {i+1, 100};
		T.push_back({A[i].S, i, 0});
		T.push_back({A[i].E, i, 0});
	}
	T.push_back({{S, S}, N+1, 0});
	T.push_back({{S, -S}, N+2, 0});
	T.push_back({{-S, -S}, N+3, 0});
	T.push_back({{-S, S}, N+4, 0});

	int L = T.size();

	set<pdd> st = {{0, 0}};
	for(int i=1; i<=N; i++) {
		for(int j=0; j<T.size(); j++) {
			if(i == T[j].id) continue;
			
			pdd pu = push(A[i], T[j].D);
			pdd lo = *st.lower_bound({pu.X - eps, pu.Y - eps});

			if(f(pu.X - lo.X) < eps && f(pu.Y - lo.Y) < eps) continue;

			bool f = (ok({T[j].D, pu}) && on(A[i], pu));
			for(int k=1; k<=N; k++) f &= !its({pu, T[j].D}, A[k]);
			if(f) {
				st.insert(pu);
				// puts("ok");
				int u = T.size();
				T.push_back({pu, i, 1});
				make_edge(u, j, dst(pu, T[j].D));
				make_edge(u, 2*i-2, 0);
			}
			// else puts("not ok");
		}
	}

	K = T.size();

	// printf("K: %d\n", K);
	// for(auto& it: T) {
	// 	printf("position(%f, %f), id: %d, pushed?: %d\n", it.D.X, it.D.Y, it.id, it.ps);
	// }

	for(int i=0; i<L; i++) {
		for(int j=i+1; j<L; j++) {
			if(!ok({T[i].D, T[j].D})) continue;
			bool f = 1;
			for(int k=1; k<=N; k++) f &= !its({T[i].D, T[j].D}, A[k]);
			if(!f) continue;
			double d;
			if(T[i].id == T[j].id) d = 0;
			else d = dst(T[i].D, T[j].D);
			// printf("(%f, %f) <----> (%f, %f), cost: %f\n", T[i].D.X, T[i].D.Y, T[j].D.X, T[j].D.Y, d);
			adj[i].push_back({j, d});
			adj[j].push_back({i, d});
		}
	}

	for(int i=0; i<2*N; i+=2) dijk(i);
	for(int i=2*N; i<2*N+4; i++) dijk(i);
	printf("%.10f", ans);
	return 0;
}

Compilation message

fences.cpp: In function 'int main()':
fences.cpp:111:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=0; j<T.size(); j++) {
                ~^~~~~~~~~
fences.cpp: In function 'int CCWs(pdd, pdd, pdd)':
fences.cpp:27:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
fences.cpp: In function 'int main()':
fences.cpp:93:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&N,&S);
  ~~~~~^~~~~~~~~~~~~~
fences.cpp:97:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lf%lf%lf%lf", &A[i].S.X, &A[i].S.Y, &A[i].E.X, &A[i].E.Y);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 25 ms 23800 KB Output is correct
2 Correct 25 ms 23804 KB Output is correct
3 Correct 25 ms 23800 KB Output is correct
4 Correct 25 ms 23800 KB Output is correct
5 Correct 26 ms 23800 KB Output is correct
6 Correct 26 ms 23804 KB Output is correct
7 Correct 26 ms 23800 KB Output is correct
8 Correct 26 ms 23804 KB Output is correct
9 Correct 27 ms 23928 KB Output is correct
10 Correct 27 ms 23928 KB Output is correct
11 Correct 26 ms 23800 KB Output is correct
12 Correct 26 ms 23800 KB Output is correct
13 Correct 26 ms 23800 KB Output is correct
14 Correct 26 ms 23804 KB Output is correct
15 Correct 26 ms 23800 KB Output is correct
16 Correct 26 ms 23800 KB Output is correct
17 Correct 25 ms 23800 KB Output is correct
18 Correct 25 ms 23800 KB Output is correct
19 Correct 25 ms 23800 KB Output is correct
20 Correct 25 ms 23800 KB Output is correct

Subtask #2
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 25 ms 23800 KB Output is correct
2 Correct 25 ms 23804 KB Output is correct
3 Correct 25 ms 23800 KB Output is correct
4 Correct 25 ms 23800 KB Output is correct
5 Correct 26 ms 23800 KB Output is correct
6 Correct 26 ms 23804 KB Output is correct
7 Correct 26 ms 23800 KB Output is correct
8 Correct 26 ms 23804 KB Output is correct
9 Correct 27 ms 23928 KB Output is correct
10 Correct 27 ms 23928 KB Output is correct
11 Correct 26 ms 23800 KB Output is correct
12 Correct 26 ms 23800 KB Output is correct
13 Correct 26 ms 23800 KB Output is correct
14 Correct 26 ms 23804 KB Output is correct
15 Correct 26 ms 23800 KB Output is correct
16 Correct 26 ms 23800 KB Output is correct
17 Correct 25 ms 23800 KB Output is correct
18 Correct 25 ms 23800 KB Output is correct
19 Correct 25 ms 23800 KB Output is correct
20 Correct 25 ms 23800 KB Output is correct
21 Correct 25 ms 23800 KB Output is correct
22 Correct 26 ms 23988 KB Output is correct
23 Correct 26 ms 23800 KB Output is correct
24 Correct 25 ms 23800 KB Output is correct
25 Correct 25 ms 23800 KB Output is correct
26 Correct 27 ms 23736 KB Output is correct
27 Correct 27 ms 23932 KB Output is correct
28 Correct 30 ms 23804 KB Output is correct
29 Correct 31 ms 23800 KB Output is correct
30 Correct 30 ms 23928 KB Output is correct
31 Correct 31 ms 23800 KB Output is correct
32 Correct 26 ms 23800 KB Output is correct
33 Correct 26 ms 23800 KB Output is correct
34 Correct 27 ms 23904 KB Output is correct
35 Correct 27 ms 23800 KB Output is correct
36 Correct 33 ms 23800 KB Output is correct
37 Correct 26 ms 23800 KB Output is correct
38 Correct 26 ms 23844 KB Output is correct
39 Correct 27 ms 23800 KB Output is correct
40 Correct 26 ms 23800 KB Output is correct
41 Correct 26 ms 23800 KB Output is correct
42 Correct 31 ms 23800 KB Output is correct
43 Correct 26 ms 23800 KB Output is correct

Subtask #3
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 25 ms 23800 KB Output is correct
2 Correct 25 ms 23804 KB Output is correct
3 Correct 25 ms 23800 KB Output is correct
4 Correct 25 ms 23800 KB Output is correct
5 Correct 26 ms 23800 KB Output is correct
6 Correct 26 ms 23804 KB Output is correct
7 Correct 26 ms 23800 KB Output is correct
8 Correct 26 ms 23804 KB Output is correct
9 Correct 27 ms 23928 KB Output is correct
10 Correct 27 ms 23928 KB Output is correct
11 Correct 26 ms 23800 KB Output is correct
12 Correct 26 ms 23800 KB Output is correct
13 Correct 26 ms 23800 KB Output is correct
14 Correct 26 ms 23804 KB Output is correct
15 Correct 26 ms 23800 KB Output is correct
16 Correct 26 ms 23800 KB Output is correct
17 Correct 25 ms 23800 KB Output is correct
18 Correct 25 ms 23800 KB Output is correct
19 Correct 25 ms 23800 KB Output is correct
20 Correct 25 ms 23800 KB Output is correct
21 Correct 25 ms 23800 KB Output is correct
22 Correct 26 ms 23988 KB Output is correct
23 Correct 26 ms 23800 KB Output is correct
24 Correct 25 ms 23800 KB Output is correct
25 Correct 25 ms 23800 KB Output is correct
26 Correct 27 ms 23736 KB Output is correct
27 Correct 27 ms 23932 KB Output is correct
28 Correct 30 ms 23804 KB Output is correct
29 Correct 31 ms 23800 KB Output is correct
30 Correct 30 ms 23928 KB Output is correct
31 Correct 31 ms 23800 KB Output is correct
32 Correct 26 ms 23800 KB Output is correct
33 Correct 26 ms 23800 KB Output is correct
34 Correct 27 ms 23904 KB Output is correct
35 Correct 27 ms 23800 KB Output is correct
36 Correct 33 ms 23800 KB Output is correct
37 Correct 26 ms 23800 KB Output is correct
38 Correct 26 ms 23844 KB Output is correct
39 Correct 27 ms 23800 KB Output is correct
40 Correct 26 ms 23800 KB Output is correct
41 Correct 26 ms 23800 KB Output is correct
42 Correct 31 ms 23800 KB Output is correct
43 Correct 26 ms 23800 KB Output is correct
44 Correct 355 ms 24296 KB Output is correct
45 Incorrect 386 ms 24312 KB Output isn't correct
46 Halted 0 ms 0 KB -