oj.uz

Submission #57064

# Submission time Handle Problem Language Result Execution time Memory
57064 2018-07-13T17:49:43 Z cki86201 Fences (JOI18_fences) C++11
100 / 100
 225 ms 3824 KB 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include <math.h>
#include <assert.h>
#include <queue>
#include <map>
#include <set>
#include <string>
#include <algorithm>
#include <iostream>
#include <functional>
#include <unordered_map>

using namespace std;
typedef pair<int, int> pii;
typedef long long ll;
#define Fi first
#define Se second
#define pb(x) push_back(x)
#define szz(x) (int)x.size()
#define rep(i, n) for(int i=0;i<n;i++)
#define all(x) x.begin(), x.end()
typedef tuple<int, int, int> t3;

struct point {
	double x, y;
	point(){}
	point(double x, double y) : x(x), y(y) {}
	point operator-(point a) { return point(x - a.x, y - a.y); }
	point operator+(point a) { return point(x + a.x, y + a.y); }
	double operator*(point a) { return x * a.x + y * a.y; }
	point operator*(double a) { return point(x * a, y * a); }
	double operator/(point a) { return x * a.y - y * a.x; }
	double length() { return hypot(x, y); }
};

vector <point> V;
int N, S;
point In[110][2];
const double EPS = 1e-9;

inline int p1_in(double x) { return -S + EPS < x && x < S - EPS; }
inline int seg1_in(double l1, double r1, double l2, double r2) {
	if(l1 > r1) swap(l1, r1);
	if(l2 > r2) swap(l2, r2);
	return max(l1, l2) + EPS < min(r1, r2);
}

int is_in(point a, point b) {
	if(fabs(a.x - b.x) <= EPS) { swap(a.x, a.y); swap(b.x, b.y); }
	if(fabs(a.x - b.x) <= EPS) {
		return p1_in(a.x) && p1_in(a.y);
	}
	if(fabs(a.y - b.y) <= EPS) {
		if(p1_in(a.y) && seg1_in(a.x, b.x, -S, S)) return 1;
		return 0;
	}
	double lx = (-S - a.x) / (b.x - a.x);
	double rx = (S - a.x) / (b.x - a.x);
	if(lx > rx) swap(lx, rx);
	double ly = (-S - a.y) / (b.y - a.y);
	double ry = (S - a.y) / (b.y - a.y);
	if(ly > ry) swap(ly, ry);
	double L = max({lx, ly, 0.0});
	double R = min({rx, ry, 1.0});
	if(L + EPS < R) return 1;
	return 0;
}

typedef pair<double, int> pdi;

vector <point> PS;
vector <pdi> E[50050];

int sign(double x) {
	if(fabs(x) <= EPS) return 0;
	return x > 0 ? 1 : -1;
}

int seg2_in(point a, point b, point c, point d) {
	return sign((b-a) / (c-a)) * sign((b-a) / (d-a)) == -1 && sign((d-c) / (a-c)) * sign((d-c) / (b-c)) == -1;
}

int meet(int a, int b) {
	point p1 = point(0, 0);
	point p2 = point(400 + sqrt(2), 1);
	return seg2_in(PS[a], PS[b], p1, p2);
}

void add_edge(int a, int b, double len = -1) {
	if(is_in(PS[a], PS[b])) return;
	int c = meet(a, b);
	if(len == -1) len = (PS[a] - PS[b]).length();
	rep(u, 2) {
		E[a<<1^u].pb(pdi(len, b<<1^u^c));
		E[b<<1^u^c].pb(pdi(len, a<<1^u));
	}
}

double dis[50050];
double get_min(int x) {
	int s = x * 2, des = s + 1;
	priority_queue <pdi, vector<pdi>, greater<pdi> > pq;
	int N = szz(PS) * 2;
	rep(i, N) dis[i] = 1e9;
	dis[s] = 0; pq.push(pdi(0, s));
	while(!pq.empty()) {
		pdi t = pq.top(); pq.pop();
		if(dis[t.Se] != t.Fi) continue;
		if(t.Se == des) return t.Fi;
		for(pdi e : E[t.Se]) {
			if(e.Fi + t.Fi < dis[e.Se]) {
				dis[e.Se] = e.Fi + t.Fi;
				pq.push(pdi(dis[e.Se], e.Se));
			}
		}
	}
	return dis[des];
}

void solve(){
	scanf("%d%d", &N, &S);
	for(int x : {-S, S}) for(int y : {-S, S}) PS.pb(point(x, y));
	rep(i, N) {
		int l = szz(PS);
		rep(j, 2) {
			int x, y; scanf("%d%d", &x, &y);
			In[i][j] = point(x, y);
			PS.pb(In[i][j]);
		}
		add_edge(l, l+1, 0);
	}
	rep(i, szz(PS)) rep(j, i) add_edge(i, j);
	rep(i, 2*N+4) rep(j, N) {
		point a = In[j][0], b = In[j][1];
		point p = PS[i];
		if((p-a) * (b-a) > EPS && (p-b) * (a-b) > EPS) {
			double v = ((p-a) * (b-a)) / ((b-a) * (b-a));
			point h = a + (b-a) * v;
			int ok = 1;
			rep(k, N) if(seg2_in(p, h, In[k][0], In[k][1])) { ok = 0; break; }
		//	printf("p = (%.1f, %.1f), a = (%.1f, %.1f), b = (%.1f, %.1f), h = (%.1f, %.1f)\n", p.x, p.y, a.x, a.y, b.x, b.y, h.x, h.y);
			if(ok) {
				int z = szz(PS);
				PS.pb(h);
				add_edge(2 * j + 4, z, 0);
				add_edge(2 * j + 5, z, 0);
				add_edge(z, i);
			}
		}
	}
	
	double ans = 1e9;
	rep(i, 2*N+4) ans = min(ans, get_min(i));
	printf("%.12f\n", ans);
}

int main(){
	int Tc = 1; //scanf("%d", &Tc);
	for(int tc=1;tc<=Tc;tc++){
		solve();
	}
	return 0;
}

Compilation message

fences.cpp: In function 'void solve()':
fences.cpp:124:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &N, &S);
  ~~~~~^~~~~~~~~~~~~~~~
fences.cpp:129:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    int x, y; scanf("%d%d", &x, &y);
              ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 1528 KB Output is correct
2 Correct 3 ms 1528 KB Output is correct
3 Correct 3 ms 1584 KB Output is correct
4 Correct 3 ms 1660 KB Output is correct
5 Correct 3 ms 1696 KB Output is correct
6 Correct 3 ms 1696 KB Output is correct
7 Correct 3 ms 1712 KB Output is correct
8 Correct 3 ms 1712 KB Output is correct
9 Correct 3 ms 1712 KB Output is correct
10 Correct 4 ms 1712 KB Output is correct
11 Correct 4 ms 1760 KB Output is correct
12 Correct 3 ms 1768 KB Output is correct
13 Correct 3 ms 1768 KB Output is correct
14 Correct 3 ms 1768 KB Output is correct
15 Correct 3 ms 1860 KB Output is correct
16 Correct 3 ms 1860 KB Output is correct
17 Correct 4 ms 1860 KB Output is correct
18 Correct 3 ms 1900 KB Output is correct
19 Correct 3 ms 1900 KB Output is correct
20 Correct 3 ms 1900 KB Output is correct

Subtask #2
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 1528 KB Output is correct
2 Correct 3 ms 1528 KB Output is correct
3 Correct 3 ms 1584 KB Output is correct
4 Correct 3 ms 1660 KB Output is correct
5 Correct 3 ms 1696 KB Output is correct
6 Correct 3 ms 1696 KB Output is correct
7 Correct 3 ms 1712 KB Output is correct
8 Correct 3 ms 1712 KB Output is correct
9 Correct 3 ms 1712 KB Output is correct
10 Correct 4 ms 1712 KB Output is correct
11 Correct 4 ms 1760 KB Output is correct
12 Correct 3 ms 1768 KB Output is correct
13 Correct 3 ms 1768 KB Output is correct
14 Correct 3 ms 1768 KB Output is correct
15 Correct 3 ms 1860 KB Output is correct
16 Correct 3 ms 1860 KB Output is correct
17 Correct 4 ms 1860 KB Output is correct
18 Correct 3 ms 1900 KB Output is correct
19 Correct 3 ms 1900 KB Output is correct
20 Correct 3 ms 1900 KB Output is correct
21 Correct 3 ms 1900 KB Output is correct
22 Correct 4 ms 1900 KB Output is correct
23 Correct 5 ms 1900 KB Output is correct
24 Correct 3 ms 1900 KB Output is correct
25 Correct 4 ms 1900 KB Output is correct
26 Correct 3 ms 1900 KB Output is correct
27 Correct 3 ms 1900 KB Output is correct
28 Correct 4 ms 1900 KB Output is correct
29 Correct 3 ms 1900 KB Output is correct
30 Correct 3 ms 1900 KB Output is correct
31 Correct 3 ms 1900 KB Output is correct
32 Correct 4 ms 1900 KB Output is correct
33 Correct 3 ms 1900 KB Output is correct
34 Correct 4 ms 1900 KB Output is correct
35 Correct 3 ms 1900 KB Output is correct
36 Correct 4 ms 1900 KB Output is correct
37 Correct 3 ms 1900 KB Output is correct
38 Correct 3 ms 1900 KB Output is correct
39 Correct 4 ms 1900 KB Output is correct
40 Correct 3 ms 1900 KB Output is correct
41 Correct 3 ms 1900 KB Output is correct
42 Correct 3 ms 1900 KB Output is correct
43 Correct 4 ms 1900 KB Output is correct

Subtask #3
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 1528 KB Output is correct
2 Correct 3 ms 1528 KB Output is correct
3 Correct 3 ms 1584 KB Output is correct
4 Correct 3 ms 1660 KB Output is correct
5 Correct 3 ms 1696 KB Output is correct
6 Correct 3 ms 1696 KB Output is correct
7 Correct 3 ms 1712 KB Output is correct
8 Correct 3 ms 1712 KB Output is correct
9 Correct 3 ms 1712 KB Output is correct
10 Correct 4 ms 1712 KB Output is correct
11 Correct 4 ms 1760 KB Output is correct
12 Correct 3 ms 1768 KB Output is correct
13 Correct 3 ms 1768 KB Output is correct
14 Correct 3 ms 1768 KB Output is correct
15 Correct 3 ms 1860 KB Output is correct
16 Correct 3 ms 1860 KB Output is correct
17 Correct 4 ms 1860 KB Output is correct
18 Correct 3 ms 1900 KB Output is correct
19 Correct 3 ms 1900 KB Output is correct
20 Correct 3 ms 1900 KB Output is correct
21 Correct 3 ms 1900 KB Output is correct
22 Correct 4 ms 1900 KB Output is correct
23 Correct 5 ms 1900 KB Output is correct
24 Correct 3 ms 1900 KB Output is correct
25 Correct 4 ms 1900 KB Output is correct
26 Correct 3 ms 1900 KB Output is correct
27 Correct 3 ms 1900 KB Output is correct
28 Correct 4 ms 1900 KB Output is correct
29 Correct 3 ms 1900 KB Output is correct
30 Correct 3 ms 1900 KB Output is correct
31 Correct 3 ms 1900 KB Output is correct
32 Correct 4 ms 1900 KB Output is correct
33 Correct 3 ms 1900 KB Output is correct
34 Correct 4 ms 1900 KB Output is correct
35 Correct 3 ms 1900 KB Output is correct
36 Correct 4 ms 1900 KB Output is correct
37 Correct 3 ms 1900 KB Output is correct
38 Correct 3 ms 1900 KB Output is correct
39 Correct 4 ms 1900 KB Output is correct
40 Correct 3 ms 1900 KB Output is correct
41 Correct 3 ms 1900 KB Output is correct
42 Correct 3 ms 1900 KB Output is correct
43 Correct 4 ms 1900 KB Output is correct
44 Correct 99 ms 3580 KB Output is correct
45 Correct 109 ms 3580 KB Output is correct
46 Correct 106 ms 3580 KB Output is correct
47 Correct 102 ms 3580 KB Output is correct
48 Correct 128 ms 3708 KB Output is correct
49 Correct 107 ms 3708 KB Output is correct
50 Correct 113 ms 3708 KB Output is correct
51 Correct 113 ms 3708 KB Output is correct
52 Correct 116 ms 3708 KB Output is correct
53 Correct 101 ms 3708 KB Output is correct
54 Correct 108 ms 3708 KB Output is correct
55 Correct 116 ms 3708 KB Output is correct
56 Correct 102 ms 3708 KB Output is correct
57 Correct 135 ms 3708 KB Output is correct
58 Correct 124 ms 3708 KB Output is correct
59 Correct 118 ms 3708 KB Output is correct
60 Correct 122 ms 3708 KB Output is correct
61 Correct 114 ms 3708 KB Output is correct
62 Correct 5 ms 3708 KB Output is correct
63 Correct 7 ms 3708 KB Output is correct
64 Correct 128 ms 3708 KB Output is correct
65 Correct 225 ms 3708 KB Output is correct
66 Correct 176 ms 3708 KB Output is correct
67 Correct 68 ms 3824 KB Output is correct
68 Correct 127 ms 3824 KB Output is correct
69 Correct 151 ms 3824 KB Output is correct
70 Correct 149 ms 3824 KB Output is correct
71 Correct 160 ms 3824 KB Output is correct
72 Correct 138 ms 3824 KB Output is correct