Submission #109730

#	Time	Username	Problem	Language	Result	Execution time	Memory
109730		Jatana	Fences (JOI18_fences)	C++17	18 / 100	14 ms	512 KiB

fences

/*
                                                                                                     
                                             `-:://:::-                                             
                                           `//:-------:/:`                                          
                                          .+:--.......--:+`                                         
                                         `+:--..`````..--//`                                        
                                         .o:--..`` ``..--:o`                                        
                                         .o:--...```..---+/`                                        
                                       `/y+o/---....---:+o.                                         
                                   `...````-os+/:---:/+o/--.`                                       
              `-/+++++/:.      `...`       :h+d+oooo+/+-`   ...                                     
            `/++//:::://++-`....`         -.`//````````:`     `..`                                  
           `o+/::------://o/`           `-` -.          -`       `..`                               
 `---.-o/:./o/::-..``..-ЗАПУСКАЕМ      ..  ..            -`        `...       ``..``                
  `....o+:-++/:--.```..-://s.        `-`  .-              -`          `-o: .-//::::/:-`             
          `:s+/:--....-::/+s-`      .-   `-                -`           -///:--------:/:`           
           ./s+//:::::://oo-``..НЕЙРОННУЮ: СЕТЬ:::::::-`РАБОТЯГИ        `+:--........--:/`          
            .:ooo+++++osso-`    `.:-...`/` ./::-------:/:`   -`         :+--..``````.--:+:...-+:-`  
             `.-/+++++/+-.-`    -.   ``:so:/:--.......--:+`  `-```````o+/+--..`````..--:o/-..:s+:.  
                 ```````:``.. `-`     -` `+:--..`````..--/+-.../.`````..-o:--.......---/o.    `     
                        `:  `:-      -.  .o:--..`` ``..--:o`   `-`      `:o+:--------:+o-`          
                         `-`-...    ..   .o/--...```..--:+/`    `-`     `oy/so/////++o/.`           
                          -/`  `-` `- ``+s/o/:---...---:++.      `-`   .-../d://///:-.`             
                `.---..``-..-    .-/..`````-oo+/:::::/+o+-        `-``-`  `-.  ````                 
             `:++++/+++++-  ..``.-/:`      /y-:/++o++/:.`..`       ./.   `-                         
            -++/::::::://+/..:-``:` ..   `-.`  ```.```    `..`   `..`-` `-                          
       ``  -o//:--....-::/++` -.-`   `-`.-`                 `..`..`  `-.-                           
  -----ss+:++/:--.```..-://s.  /.     `::                    `-:.     ./`                           
  `````/:..+o/::-..``.--:/+s. ..-`   `-``-`                 ..` `-`  `-`-`                          
          `-s+/::-----::/+oo---``-` ..    .:-    ```      .-`     .-.-  `-`                         
           `:oo+//::://+os/..:`..-/:`      :y.-:::::::.`.-`        ./-`  `-`                        
            `./+oooooooo+/.`-    .-:...`.. .//:-------://`        `- `..` `:.                       
              ``.-::::-.``-/`  `-` `-  `oo:+:--.......--:/`      `-    `.:--h.``..```               
                          -.-`.-    .-   `+:--..`````..--//`    `-       /s-//::::::::.             
                         -` `/-      ..  .o:--..`` ``..--:o.```.-        `//:--------://`           
                        -` .-`.-`     -.`-o/--...```..--:+/.``-:....``:-.+:--....`...--:+`          
                       ..`-.   `-.   ``:os:o/:---...---:++.  `-     ``///+:-..``````.--:+-````-.`   
              `.:///////.-`      .:-..` -``-+o+/:::::/+o/.  `-         `:+:-..`````..--:o/:--/ys+-  
            `-++///////+o/. ``....`-.    :` `.:++++++/:.`  .-           -o/---......---/o.   `.`    
           `++//:-----::/+o:..`     .-`   :    ```````    .-           `+so+:--------:++-`          
  `````:-``:o/::-..`..--:/+o`         -.  `-             .-          `../../+o+////+o+:.`           
  -----syo/o+/:--.```..-://s.          .-` `-           .-        `...     ``-:////:-``             
       .` `/s//:--....-::/+s.            -. `-`        .-       `..`                                
           .+o+/:::--:://+s/-..`          .::+y  ```  .-     `..`                                   
            ./oo++////+oso-`   `....       :y-+:::::::/`   ...                                      
             `.:+oooooo/-`         `....-. .//:-------:/:-.`                                        
                ``...``                 /+:+:--.......--:+`                                         
                                         `+:--..`````..--//`                                        
                                         .o:--..`` ``..--:o`                                        
                                         .+/--...```..--:+/`                                        
                                         `-o/:---...---:++.                                         
                                          `-+o+/:---:/+o/.                                          
                                            `.:+oooo+/-.`                                           
                                               ``````                                               
*/

#ifdef aimbot
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")
#endif

#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <map>
#include <set>
#include <queue>
#include <ostream>
#include <istream>
#include <typeinfo>
#include <iomanip>
#include <cstdio>
#include <cstdlib>
#include <cassert>
#include <limits>
#include <fstream>
#include <array>
#include <list>
#include <bitset>
#include <functional>
#include <random>
#include <cstring>
#include <chrono>

#define random escape__from__random__aetuhoetnuhshe
#define mt make_tuple
#define x first
#define y second
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define umap unordered_map
#define uset unordered_set
#define elif else if
#define len(v) ((int)v.size())
#define f(i, n) for (int i = 0; i < (n); i++)
#define rof(i, n) for (int i = ((n) - 1); i >= 0; i--)
#define apply(v, act) for (auto &x : v) { act; }
#define log(args...) {string s = #args;deque<string> deq;\
string buf = "";int bal = 0;for (char c : s) {\
if (c == '(' || c == '[' || c == '{') {bal++;\
} else if (c == ')' || c == ']' || c == '}') {\
bal--;} else {if (bal == 0) {if (c == ',') {\
deq.pb(buf);buf = "";} else {if (c != ' ') {\
buf += c;}}}}}if (!buf.empty()) {deq.pb(buf);}\
smart_io::precall_print();smart_io::_print(deq, args);}

inline int min(const int &x, const int &y) { return (((y-x)>>(32-1))&(x^y))^x; }
inline int max(const int &x, const int &y) { return (((y-x)>>(32-1))&(x^y))^y; }
inline long long min(const long long &x, const long long &y) { return (((y-x)>>(64-1))&(x^y))^x; }
inline long long max(const long long &x, const long long &y) { return (((y-x)>>(64-1))&(x^y))^y; }

#define print    \
smart_io::precall_print(); \
cout,

#define scan cin,

#ifdef fast_allocator
const int MAXMEM = 200 * 1000 * 1024;
char _memory[MAXMEM];
size_t _ptr = 0;
void* operator new(size_t _x) { _ptr += _x; assert(_ptr < MAXMEM); return _memory + _ptr - _x; }
void operator delete (void*) noexcept {}
#endif

using namespace std;

char string_in_buffer[(int)260];


void fast_scan(int &x) { scanf("%d", &x); }
void fast_scan(long long &x) { scanf("%lld", &x); }
void fast_scan(unsigned long long &x) { scanf("%llu", &x); }
void fast_scan(double &x) { scanf("%lf", &x); }
void fast_scan(long double &x) { scanf("%Lf", &x); }
void fast_scan(char &x) {
	scanf("%c", &x);
	if (x == '\n') {
		fast_scan(x);
	}
}
void fast_scan(string &x) {
	scanf("%s", string_in_buffer);
	x = string(string_in_buffer);
}

template<class TFirst, class TSecond>
void fast_scan(pair<TFirst, TSecond> &p) {
	fast_scan(p.first);
	fast_scan(p.second);
}

template <class T>
void fast_scan(vector<T> &v) {
	for (auto &x : v) fast_scan(x);
}

void fast_print(const int &x) { printf("%d", x); }
void fast_print(const unsigned int &x) { printf("%u", x); }
void fast_print(const long long &x) { printf("%lld", x); }
void fast_print(const unsigned long long &x) { printf("%llu", x); }
void fast_print(const double &x) { printf("%.15lf", x); }
void fast_print(const long double &x) { printf("%.15Lf", x); }
void fast_print(const char &x) { printf("%c", x); };
void fast_print(const string &x) { printf("%s", x.c_str());}
void fast_print(const char v[]) { fast_print((string)v); }

template<class TFirst, class TSecond>
void fast_print(const pair<TFirst, TSecond> &p) {
	fast_print(p.first);
	fast_print(' ');
	fast_print(p.second);
}

template <class T>
void fast_print(const vector<T> &v) {
	if (v.empty()) return;
	fast_print(v[0]);
	for (int i = 1; i < v.size(); i++) {
		fast_print(' ');
		fast_print(v[i]);
	}
}

template <class T>
void fast_print(const vector<vector<T>> &v) {
	if (v.empty()) return;
	fast_print(v[0]);
	for (int i = 1; i < v.size(); i++) {
		fast_print('\n');
		fast_print(v[i]);
	}
}

template <class T>
void fast_print(const T &v) {
	for (const auto &x : v) {
		fast_print(x);
		fast_print(' ');
	}
}


using namespace std;


namespace smart_io {
	string print_start = "";
	string sep = " ";
	bool first_print = false;
	
	void precall_print() {
		fast_print(print_start);
		print_start = "\n";
		first_print = true;
	}
	
	void _print(deque<string>) {}
	template<class T, class... Args>
	void _print(deque<string> names, T elem, Args... args) {
		if (!first_print) {
			fast_print("\n");
		} else {
			first_print = false;
		}
		fast_print(names.front());
		fast_print(" = ");
		fast_print(elem);
		names.pop_front();
		_print(names, args...);
	}
} //namespace smart_io


template <class T>
ostream &operator,(ostream &os, const T &object) {
	if (!smart_io::first_print) {
		fast_print(smart_io::sep);
	} else {
		smart_io::first_print = false;
	}
	fast_print(object);
	return os;
}

template <class T>
istream &operator,(istream &is, T &object) {
	fast_scan(object);
	return is;
}

namespace random {
	using namespace std::chrono;
	mt19937 rng(duration_cast< milliseconds >(
											  system_clock::now().time_since_epoch()
											  ).count());
	uniform_real_distribution<> prob_dist(0.0, 1.0);
};

namespace typedefs {
	typedef long long ll;
	typedef unsigned long long ull;
	typedef pair<int, int> pii;
	typedef long double ld;
	typedef pair<ld, ld> pdd;
}

namespace numbers_operation {
	template<class T>
	T floor_mod(T a, T b) {
		if (a >= 0 && b >= 0) return a % b;
		if (a <= 0 && b <= 0) return a % b;
		return abs(b) - (abs(a) % abs(b));
	}
}

using namespace numbers_operation;
using namespace typedefs;
using namespace random;

int n, S;
vector<pdd> A, B;


ld dist(pdd a, pdd b) {
	return hypot(a.x - b.x, a.y - b.y);
}

pdd operator+(pdd a, pdd b) {
	return mp(a.x + b.x, a.y + b.y);
}

pdd operator-(pdd a, pdd b) {
	return mp(a.x - b.x, a.y - b.y);
}

pdd operator*(pdd p, ld x) {
	return mp(p.x * x, p.y * x);
}

ld operator^(pdd a, pdd b) {
	return a.x * b.y - a.y * b.x;
}

pdd nearest(pdd a, pdd b, pdd c) {
	ld l = 0;
	ld r = 1;
	f(test, 100) {
		ld m1 = l + (r - l) / 3;
		ld m2 = r - (r - l) / 3;
		if (dist(a + (b - a) * m1, c) < dist(a + (b - a) * m2, c)) {
			r = m2;
		} else {
			l = m1;
		}
	}
	return (a + (b - a) * l);
}

struct Line {
	ld a, b, c;
	Line(pdd p, pdd q) {
		pdd vec = p - q;
		a = -vec.y;
		b = vec.x;
		c = -a * p.x - b * p.y;
	}
	ld equate(pdd p) {
		return a * p.x + b * p.y + c;
	}
};

const ld EPS = 1e-15;
vector<Line> quad;

int sign(ld x) {
	if (x > 0) return 1;
	if (x < 0) return -1;
	return 0;
}

bool normal(pdd a, pdd b) {
	if (dist(a, b) < EPS) return true;
	{
		if (all_of(quad.begin(), quad.end(), [&a](Line l) {
			return l.equate(a) > 0;
		})) return false;
		if (all_of(quad.begin(), quad.end(), [&b](Line l) {
			return l.equate(b) > 0;
		}))	return false;
	}
	{
		if (all_of(quad.begin(), quad.end(), [&a, &b](Line l) {
			return sign(l.equate(a)) == sign(l.equate(b));
		}))	return true;
	}
	{
		pdd m = (a + b) * 0.5;
		if (!normal(a, m)) return false;
		return normal(m, b);
	}
}

vector<vector<pdd>> go;
vector<pdd> pts;

signed main(signed argc, char *argv[]) {
	scan n, S;
	A.resize(n);
	B.resize(n);
	f(i, n) {
		scan A[i], B[i];
		pts.pb(A[i]);
		pts.pb(B[i]);
	}
	// n += 4;
	{
		// vector<pdd> _pts = {
		// 	mp(-S, -S),
		// 	mp(-S, S),
		// 	mp(S, S),
		// 	mp(S, -S)
		// };
		// print "Polygon";
		// for (pdd p : _pts) {
		// 	print p;
		// }
		// print "...";
		// f(i, 4) {
		// 	A.pb(_pts[i]);
		// 	B.pb(_pts[(i + 1) % 4]);
		// }
	}
	{
		vector<pdd> _pts = {
			mp(-S + EPS, -S + EPS),
			mp(-S + EPS, S - EPS),
			mp(S - EPS, S - EPS),
			mp(S - EPS, -S + EPS)
		};
		f(i, 4) {
			quad.emplace_back(_pts[i], _pts[(i + 1) % 4]);
		}
	}
	pts.pb(mp(-S, S));
	pts.pb(mp(S, S));
	pts.pb(mp(-S, -S));
	pts.pb(mp(S, -S));
	sort(pts.begin(), pts.end());
	pts.resize(unique(pts.begin(), pts.end()) - pts.begin());
	auto id = [](pdd p) {
		return lower_bound(pts.begin(), pts.end(), p) - pts.begin();
	};
	go.resize(len(pts), vector<pdd>(len(pts), mp(1e18, 1e18)));
	f(i, len(pts)) {
		f(j, len(pts)) {
			go[i][j] = pts[i];
		}
	}
	f(i, n) {
		f(j, len(pts)) {
			go[id(B[i])][j] = go[id(A[i])][j] = nearest(A[i], B[i], pts[j]);
		}
	}
	f(i, n) {
		// go[id(A[i])][id(B[i])] = B[i];
		// go[id(B[i])][id(A[i])] = A[i];
	}
	pdd R = mp(rng() % 1000 + 500, rng() % 1000 + 500);
	auto inter = [&R](pdd a, pdd b) {
		if (dist(a, b) < EPS) return false;
		return ((R ^ a) * (R ^ b)) < 0 && ((b - a) ^ (R - a)) * ((b - a) ^ (mp(0, 0) - a)) < 0;
	};

	vector<vector<ld>> dp(len(pts) * 2, vector<ld>(len(pts) * 2, 1e18));
	vector<vector<int>> pref(len(pts) * 2, vector<int>(len(pts) * 2, -1));
	f(i, n) {
		dp[2 * i][2 * i] = 0;
	}
	f(i, len(pts)) {
		f(j, len(pts)) {
			if (go[i][j].x == 1e18) continue;
			if (normal(pts[i], go[i][j]) && normal(go[i][j], pts[j])) {
				f(t, 2) {
					int c = inter(pts[i], go[i][j]) + inter(go[i][j], pts[j]);
					dp[2 * i + t][2 * j + ((t + c) % 2)] = dist(go[i][j], pts[j]);
					pref[2 * i + t][2 * j + ((t + c) % 2)] = 2 * i + t;
				}
			}
			if (normal(pts[j], go[j][i]) && normal(go[j][i], pts[i])) {
				f(t, 2) {
					int c = inter(pts[j], go[j][i]) + inter(go[j][i], pts[i]);
					if (dist(go[j][i], pts[i]) < dp[2 * i + t][2 * j + ((t + c) % 2)]) {
						dp[2 * i + t][2 * j + ((t + c) % 2)] = dist(go[j][i], pts[i]);
						pref[2 * i + t][2 * j + ((t + c) % 2)] = 2 * i + t;
					}
				}
			}
		}
	}
	for (int k = 0; k < len(dp); k++) {
		for (int i = 0; i < len(dp); i++) {
			for (int j = 0; j < len(dp); j++) {
				if (dp[i][j] > dp[i][k] + dp[k][j]) {
					dp[i][j] = dp[i][k] + dp[k][j];
					pref[i][j] = pref[k][j];
				}
			}
		}
	}
	ld rez = 1e18;
	int cur = -1;
	f(i, len(pts)) {
		if (rez > dp[i * 2][i * 2 + 1]) {
			rez = dp[i * 2][i * 2 + 1];
			cur = i * 2;
		}
	}
	int start = cur;
	cur++;
	// log(len(pts));
	vector<pdd> path;
	// while (cur != start) {
		// path.pb(pts[cur / 2]);
		// path.pb(go[pref[start][cur] / 2][cur / 2]);
		// cur = pref[start][cur];
	// }
	// log(R);
	path.pb(pts[cur / 2]);
	f(i, len(path)) {
		// print path[i], i;
		// print (int)inter(path[i], path[(i + 1) % len(path)]);
	}
	print rez;
}

Compilation message (stderr)

fences.cpp: In function 'int main(int, char**)':
fences.cpp:486:6: warning: unused variable 'start' [-Wunused-variable]
  int start = cur;
      ^~~~~
fences.cpp: In function 'void fast_scan(int&)':
fences.cpp:138:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 void fast_scan(int &x) { scanf("%d", &x); }
                          ~~~~~^~~~~~~~~~
fences.cpp: In function 'void fast_scan(long long int&)':
fences.cpp:139:37: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 void fast_scan(long long &x) { scanf("%lld", &x); }
                                ~~~~~^~~~~~~~~~~~
fences.cpp: In function 'void fast_scan(long long unsigned int&)':
fences.cpp:140:46: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 void fast_scan(unsigned long long &x) { scanf("%llu", &x); }
                                         ~~~~~^~~~~~~~~~~~
fences.cpp: In function 'void fast_scan(double&)':
fences.cpp:141:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 void fast_scan(double &x) { scanf("%lf", &x); }
                             ~~~~~^~~~~~~~~~~
fences.cpp: In function 'void fast_scan(long double&)':
fences.cpp:142:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 void fast_scan(long double &x) { scanf("%Lf", &x); }
                                  ~~~~~^~~~~~~~~~~
fences.cpp: In function 'void fast_scan(char&)':
fences.cpp:144:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%c", &x);
  ~~~~~^~~~~~~~~~
fences.cpp: In function 'void fast_scan(std::__cxx11::string&)':
fences.cpp:150:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s", string_in_buffer);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 18 / 18
• Subtask 2: 0 / 33
• Subtask 3: 0 / 49