oj.uz

Submission #132158

# Submission time Handle Problem Language Result Execution time Memory
132158 2019-07-18T11:12:07 Z onjo0127 Fences (JOI18_fences) C++11
18 / 100
 26 ms 23848 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; };
struct edg { int X; double Y; bool IT; };
 
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) {
	double tmp = CCW(A, B, C);
	if(f(tmp) < eps) return 0;
	if(tmp < 0) return -1;
	if(tmp > 0) return +1;
}
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
	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<edg> 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}});
	return !f;
}
 
void dijk(int st) {
	// printf("start: (%d, %d)\n", T[st].D.X, T[st].D.Y);
	vector<pii> rec = {{0, st}};
	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) || n.v > ans) 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) continue;
		for(auto& it: adj[n.id]) {
			int tc = n.c;
			if(it.IT) tc = 1 - tc;
			if(D[tc][it.X] > n.v + it.Y) {
				D[tc][it.X] = n.v + it.Y;
				rec.push_back({tc, it.X});
				pq.push({D[tc][it.X], tc, it.X});
			}
		}
	}
	ans = min(ans, D[1][st]);
	for(auto& it: rec) D[it.X][it.Y] = 1e9;
}
 
void make_edge(int u, int v, double c, bool it) {
	// printf("u: %d, v: %d, (%f, %f) -- (%f, %f), cost: %f, cross: %d\n", u, v, T[u].D.X, T[u].D.Y, T[v].D.X, T[v].D.Y, c, it);
	adj[u].push_back({v, c, it});
	adj[v].push_back({u, c, it});
}
 
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});
 
	K = T.size();
 
	for(int i=1; i<=N; i++) {
		make_edge(2*i-2, 2*i-1, 0, its(A[i], I));
		for(int j=0; j<K; j++) {
			if(i == T[j].id) continue;
			pdd pu = push(A[i], T[j].D);
			double dp = dst(pu, T[j].D), ds = dst(T[j].D, A[i].S), de = dst(T[j].D, A[i].E);
			if(!ok({T[j].D, pu}) || !on(A[i], pu)) dp = 1e9;
			if(!ok({T[j].D, A[i].S})) ds = 1e9;
			if(!ok({T[j].D, A[i].E})) de = 1e9;
			if(dp < 1e8) make_edge(j, 2*i-2, dp, its({pu, T[j].D}, I) || its({pu, A[i].S}, I));
			if(ds < 1e8) make_edge(j, 2*i-2, ds, its({A[i].S, T[j].D}, I));
			if(de < 1e8) make_edge(j, 2*i-1, de, its({A[i].E, T[j].D}, I));
		}
	}
 
	for(int i=2*N; i<2*N+4; i++) {
		for(int j=i+1; j<2*N+4; j++) {
			if(!ok({T[i].D, T[j].D})) continue;
			make_edge(i, j, dst(T[i].D, T[j].D), its({T[i].D, T[j].D}, I));
		}
	}
 
	// 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<K; i++) D[0][i] = D[1][i] = 1e9;
	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:92:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&N,&S);
  ~~~~~^~~~~~~~~~~~~~
fences.cpp:96:8: 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);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fences.cpp: In function 'int CCWs(pdd, pdd, pdd)':
fences.cpp:28:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

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 23800 KB Output is correct
3 Correct 25 ms 23800 KB Output is correct
4 Correct 25 ms 23800 KB Output is correct
5 Correct 25 ms 23800 KB Output is correct
6 Correct 25 ms 23800 KB Output is correct
7 Correct 24 ms 23764 KB Output is correct
8 Correct 25 ms 23800 KB Output is correct
9 Correct 25 ms 23800 KB Output is correct
10 Correct 24 ms 23800 KB Output is correct
11 Correct 25 ms 23804 KB Output is correct
12 Correct 25 ms 23800 KB Output is correct
13 Correct 25 ms 23800 KB Output is correct
14 Correct 25 ms 23800 KB Output is correct
15 Correct 25 ms 23800 KB Output is correct
16 Correct 25 ms 23800 KB Output is correct
17 Correct 25 ms 23800 KB Output is correct
18 Correct 24 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
0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 25 ms 23800 KB Output is correct
2 Correct 25 ms 23800 KB Output is correct
3 Correct 25 ms 23800 KB Output is correct
4 Correct 25 ms 23800 KB Output is correct
5 Correct 25 ms 23800 KB Output is correct
6 Correct 25 ms 23800 KB Output is correct
7 Correct 24 ms 23764 KB Output is correct
8 Correct 25 ms 23800 KB Output is correct
9 Correct 25 ms 23800 KB Output is correct
10 Correct 24 ms 23800 KB Output is correct
11 Correct 25 ms 23804 KB Output is correct
12 Correct 25 ms 23800 KB Output is correct
13 Correct 25 ms 23800 KB Output is correct
14 Correct 25 ms 23800 KB Output is correct
15 Correct 25 ms 23800 KB Output is correct
16 Correct 25 ms 23800 KB Output is correct
17 Correct 25 ms 23800 KB Output is correct
18 Correct 24 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 23800 KB Output is correct
23 Correct 25 ms 23800 KB Output is correct
24 Correct 25 ms 23800 KB Output is correct
25 Correct 26 ms 23800 KB Output is correct
26 Correct 26 ms 23800 KB Output is correct
27 Correct 25 ms 23780 KB Output is correct
28 Correct 25 ms 23848 KB Output is correct
29 Correct 25 ms 23800 KB Output is correct
30 Correct 26 ms 23800 KB Output is correct
31 Correct 25 ms 23800 KB Output is correct
32 Correct 25 ms 23800 KB Output is correct
33 Correct 25 ms 23800 KB Output is correct
34 Correct 25 ms 23800 KB Output is correct
35 Correct 25 ms 23800 KB Output is correct
36 Correct 25 ms 23800 KB Output is correct
37 Correct 25 ms 23800 KB Output is correct
38 Correct 25 ms 23800 KB Output is correct
39 Incorrect 25 ms 23800 KB Output isn't correct
40 Halted 0 ms 0 KB -

Subtask #3
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 25 ms 23800 KB Output is correct
2 Correct 25 ms 23800 KB Output is correct
3 Correct 25 ms 23800 KB Output is correct
4 Correct 25 ms 23800 KB Output is correct
5 Correct 25 ms 23800 KB Output is correct
6 Correct 25 ms 23800 KB Output is correct
7 Correct 24 ms 23764 KB Output is correct
8 Correct 25 ms 23800 KB Output is correct
9 Correct 25 ms 23800 KB Output is correct
10 Correct 24 ms 23800 KB Output is correct
11 Correct 25 ms 23804 KB Output is correct
12 Correct 25 ms 23800 KB Output is correct
13 Correct 25 ms 23800 KB Output is correct
14 Correct 25 ms 23800 KB Output is correct
15 Correct 25 ms 23800 KB Output is correct
16 Correct 25 ms 23800 KB Output is correct
17 Correct 25 ms 23800 KB Output is correct
18 Correct 24 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 23800 KB Output is correct
23 Correct 25 ms 23800 KB Output is correct
24 Correct 25 ms 23800 KB Output is correct
25 Correct 26 ms 23800 KB Output is correct
26 Correct 26 ms 23800 KB Output is correct
27 Correct 25 ms 23780 KB Output is correct
28 Correct 25 ms 23848 KB Output is correct
29 Correct 25 ms 23800 KB Output is correct
30 Correct 26 ms 23800 KB Output is correct
31 Correct 25 ms 23800 KB Output is correct
32 Correct 25 ms 23800 KB Output is correct
33 Correct 25 ms 23800 KB Output is correct
34 Correct 25 ms 23800 KB Output is correct
35 Correct 25 ms 23800 KB Output is correct
36 Correct 25 ms 23800 KB Output is correct
37 Correct 25 ms 23800 KB Output is correct
38 Correct 25 ms 23800 KB Output is correct
39 Incorrect 25 ms 23800 KB Output isn't correct
40 Halted 0 ms 0 KB -