oj.uz

답안 #132036

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
132036 2019-07-18T08:29:36 Z 이온조(#3189) Fences (JOI18_fences) C++14
51 / 100
 1000 ms 242884 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) {
	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<pid> adj[1000009];
line A[111];
int N, S, K;
double ans = 1e9, D[2][1000009];
bool IT[40009][40009];

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[n.id][it.X]) 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) {
	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();

	for(int i=1; i<=N; i++) {
		make_edge(2*i-2, 2*i-1, 0);
		for(int j=0; j<T.size(); 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(min({ds, de, dp}) == 1e9) continue;
			if(dp <= ds && dp <= de) {
				int u = T.size();
				T.push_back({pu, i, 1});
				make_edge(u, j, dp);
				make_edge(u, 2*i-2, 0);
				continue;
			}
			if(ds <= de) make_edge(j, 2*i-2, ds);
			else make_edge(j, 2*i-1, de);
		}
	}

	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));
		}
	}

	K = T.size();

	for(int i=0; i<K; i++) {
		for(int j=i+1; j<K; j++) {
			if(its({T[i].D, T[j].D}, I)) IT[i][j] = IT[j][i] = 1;
		}
	}

	// 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);
	// }

	srand(14341);
	for(int i=0; i<K; i++) D[0][i] = D[1][i] = 1e9;
	for(int i=0; i<2*N; i+=2) if(N <= 50 || rand()%4 == 1) 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:109:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=0; j<T.size(); j++) {
                ~^~~~~~~~~
fences.cpp:105:6: warning: unused variable 'L' [-Wunused-variable]
  int L = T.size();
      ^
fences.cpp:91:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&N,&S);
  ~~~~~^~~~~~~~~~~~~~
fences.cpp:95:8: 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:27:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

Subtask #1
18.0 / 18.0

# 결과 실행 시간 메모리 Grader output
1 Correct 25 ms 23804 KB Output is correct
2 Correct 25 ms 23800 KB Output is correct
3 Correct 25 ms 23800 KB Output is correct
4 Correct 24 ms 23800 KB Output is correct
5 Correct 24 ms 23800 KB Output is correct
6 Correct 25 ms 23800 KB Output is correct
7 Correct 25 ms 23800 KB Output is correct
8 Correct 24 ms 23800 KB Output is correct
9 Correct 24 ms 23800 KB Output is correct
10 Correct 25 ms 23800 KB Output is correct
11 Correct 25 ms 23784 KB Output is correct
12 Correct 24 ms 23928 KB Output is correct
13 Correct 25 ms 23928 KB Output is correct
14 Correct 25 ms 23928 KB Output is correct
15 Correct 25 ms 23800 KB Output is correct
16 Correct 26 ms 23800 KB Output is correct
17 Correct 24 ms 23800 KB Output is correct
18 Correct 24 ms 23928 KB Output is correct
19 Correct 25 ms 23800 KB Output is correct
20 Correct 24 ms 23800 KB Output is correct

Subtask #2
33.0 / 33.0

# 결과 실행 시간 메모리 Grader output
1 Correct 25 ms 23804 KB Output is correct
2 Correct 25 ms 23800 KB Output is correct
3 Correct 25 ms 23800 KB Output is correct
4 Correct 24 ms 23800 KB Output is correct
5 Correct 24 ms 23800 KB Output is correct
6 Correct 25 ms 23800 KB Output is correct
7 Correct 25 ms 23800 KB Output is correct
8 Correct 24 ms 23800 KB Output is correct
9 Correct 24 ms 23800 KB Output is correct
10 Correct 25 ms 23800 KB Output is correct
11 Correct 25 ms 23784 KB Output is correct
12 Correct 24 ms 23928 KB Output is correct
13 Correct 25 ms 23928 KB Output is correct
14 Correct 25 ms 23928 KB Output is correct
15 Correct 25 ms 23800 KB Output is correct
16 Correct 26 ms 23800 KB Output is correct
17 Correct 24 ms 23800 KB Output is correct
18 Correct 24 ms 23928 KB Output is correct
19 Correct 25 ms 23800 KB Output is correct
20 Correct 24 ms 23800 KB Output is correct
21 Correct 24 ms 23928 KB Output is correct
22 Correct 24 ms 24056 KB Output is correct
23 Correct 25 ms 24028 KB Output is correct
24 Correct 30 ms 23928 KB Output is correct
25 Correct 25 ms 23928 KB Output is correct
26 Correct 25 ms 23928 KB Output is correct
27 Correct 25 ms 23928 KB Output is correct
28 Correct 30 ms 23928 KB Output is correct
29 Correct 30 ms 23928 KB Output is correct
30 Correct 25 ms 23952 KB Output is correct
31 Correct 25 ms 23928 KB Output is correct
32 Correct 25 ms 23928 KB Output is correct
33 Correct 25 ms 24056 KB Output is correct
34 Correct 25 ms 23928 KB Output is correct
35 Correct 30 ms 24316 KB Output is correct
36 Correct 26 ms 24312 KB Output is correct
37 Correct 25 ms 23928 KB Output is correct
38 Correct 24 ms 23800 KB Output is correct
39 Correct 25 ms 24056 KB Output is correct
40 Correct 25 ms 23800 KB Output is correct
41 Correct 25 ms 23928 KB Output is correct
42 Correct 24 ms 24056 KB Output is correct
43 Correct 26 ms 24568 KB Output is correct

Subtask #3
0 / 49.0

# 결과 실행 시간 메모리 Grader output
1 Correct 25 ms 23804 KB Output is correct
2 Correct 25 ms 23800 KB Output is correct
3 Correct 25 ms 23800 KB Output is correct
4 Correct 24 ms 23800 KB Output is correct
5 Correct 24 ms 23800 KB Output is correct
6 Correct 25 ms 23800 KB Output is correct
7 Correct 25 ms 23800 KB Output is correct
8 Correct 24 ms 23800 KB Output is correct
9 Correct 24 ms 23800 KB Output is correct
10 Correct 25 ms 23800 KB Output is correct
11 Correct 25 ms 23784 KB Output is correct
12 Correct 24 ms 23928 KB Output is correct
13 Correct 25 ms 23928 KB Output is correct
14 Correct 25 ms 23928 KB Output is correct
15 Correct 25 ms 23800 KB Output is correct
16 Correct 26 ms 23800 KB Output is correct
17 Correct 24 ms 23800 KB Output is correct
18 Correct 24 ms 23928 KB Output is correct
19 Correct 25 ms 23800 KB Output is correct
20 Correct 24 ms 23800 KB Output is correct
21 Correct 24 ms 23928 KB Output is correct
22 Correct 24 ms 24056 KB Output is correct
23 Correct 25 ms 24028 KB Output is correct
24 Correct 30 ms 23928 KB Output is correct
25 Correct 25 ms 23928 KB Output is correct
26 Correct 25 ms 23928 KB Output is correct
27 Correct 25 ms 23928 KB Output is correct
28 Correct 30 ms 23928 KB Output is correct
29 Correct 30 ms 23928 KB Output is correct
30 Correct 25 ms 23952 KB Output is correct
31 Correct 25 ms 23928 KB Output is correct
32 Correct 25 ms 23928 KB Output is correct
33 Correct 25 ms 24056 KB Output is correct
34 Correct 25 ms 23928 KB Output is correct
35 Correct 30 ms 24316 KB Output is correct
36 Correct 26 ms 24312 KB Output is correct
37 Correct 25 ms 23928 KB Output is correct
38 Correct 24 ms 23800 KB Output is correct
39 Correct 25 ms 24056 KB Output is correct
40 Correct 25 ms 23800 KB Output is correct
41 Correct 25 ms 23928 KB Output is correct
42 Correct 24 ms 24056 KB Output is correct
43 Correct 26 ms 24568 KB Output is correct
44 Execution timed out 1085 ms 242884 KB Time limit exceeded
45 Halted 0 ms 0 KB -