Submission #349590

#	Time	Username	Problem	Language	Result	Execution time	Memory
349590		CaroLinda	Printed Circuit Board (CEOI12_circuit)	C++11	95 / 100	186 ms	30932 KiB

circuit

#include <bits/stdc++.h>
 
#define sz(x) (int)(x.size())
#define debug printf
#define lp(i,a,b) for(int i = a ; i < b; i++)
#define pb push_back
#define ff first
#define ss second
#define mk make_pair
#define pii pair<int,int>
#define ll long long 
#define all(x) x.begin(),x.end()
 
const int MAX = 2e5+5 ;
 
using namespace std ;
 
char c ;
void readInt(int &num)
{
	num = 0 ;
	for(c = getchar() ; (c > 47 && c <58 ) ; c = getchar() )
		num = num*10 + c - 48 ;
}
 
void readLong(ll &num ) 
{
	num = 0 ;
	for(c = getchar() ; (c> 47 && c < 58 ) ; c = getchar() )
		num = num*10 + c - 48 ;
}
 
int N ;
int myId[MAX] ;
double num[MAX], den[MAX] ;
bool canceled[MAX] ;
 
struct Point
{
 
    ll x , y ;
 
    Point(ll x=0, ll y=0):x(x), y(y) {}
    
    bool operator == ( Point other ) const { return x == other.x && y == other.y ; }
    bool operator != (Point other ) const { return x != other.x || y != other.y ; }
    Point operator - (Point other) const { return Point(x-other.x, y-other.y) ; } 
    ll operator % (Point other) const { return x*other.y - y*other.x ; }
    ll operator *(Point other) const { return x*other.x + y*other.y ; }
    void read() { scanf("%lld %lld", &x, &y) ; }
} ;
 
struct Line
{
	Point p1, p2 ; 
	double cte ;
	Line( Point p1 = Point(0,0) , Point p2 = Point(0,0) ) : p1(p1) , p2(p2) {} 
} t ;
 
  
double  dx , dy ;
 
double num1, num2, den1, den2 , auxDx ,auxDy ;
 
struct Seg
{
 
	Line tree[MAX*2] ;
	int n ;
	int l[MAX*2], r[MAX*2] ;
 
	void ini()
	{
		for(int i= n ; i < 2*n ; i++ ) l[i] = r[i] = i - n ;
 
		for(int i= n-1 , lef, rig ; i > 0 ; i-- )
		{
			lef = i<<1 , rig = i<<1|1 ;
			l[i] = ( l[lef] < l[rig] ) ? l[lef] : l[rig] ;
			r[i] = ( r[lef] > r[rig] ) ? r[lef] : r[rig] ;
		}
 
	}
 
	void upd(int pos )
	{
		if( tree[pos].p1 == Point(0,0) ) return (void)(tree[pos] = t ) ; 
			 
		auxDx = (tree[pos].p1.x - tree[pos].p2.x ) ;
		auxDy = (tree[pos].p1.y - tree[pos].p2.y ) ;
 
		for(auto e : {l[pos] , r[pos] } ) 
		{
			num1 = den[e] * tree[pos].cte ;
			den1 = den[e] * auxDy - num[e] * auxDx ;
			num2 = den[e] * t.cte ;
			den2 = den[e] * dy - num[e] * dx ;
 
			if( tree[pos].p1.x == tree[pos].p2.x ) num1 = tree[pos].p1.x, den1 = 1LL ;
			if(t.p1.x == t.p2.x ) num2 = t.p1.x , den2 = 1LL ;
 
			if( (num1/den1) < (num2/den2) ) return ;
 
		}
		tree[pos] = t ;
 
	}
 
	void addLine(int l, int r )
	{
		dy = ( t.p1.y - t.p2.y ) ;
		dx = (t.p1.x-t.p2.x ) ;
 
		for( l += n , r += n ; l < r ; l >>= 1 , r >>= 1 )
		{
			if(l&1) 
			{
				upd(l) ;
				l++ ;
			}
			if(r&1) upd(--r) ;
		}			
	}
 
	bool qry(int pos, Point p )
	{

		for(pos += n ; pos > 0 ; pos >>= 1 )
		{
			if( tree[pos].p1 == Point(0,0) || tree[pos].p1 == p || tree[pos].p2 == p ) continue ;	
 
			ll val1 = (tree[pos].p2 - tree[pos].p1)%(p-tree[pos].p1) ;
			ll val2 = (tree[pos].p2-tree[pos].p1)%(Point(0,0)-tree[pos].p1 ) ;
 
			if( (val1 < 0 ) != (val2 < 0)  ) return false ;
			
		}
 
		return true ;
	}
  
} seg ;
 
int main()
{
 
	readInt(N) ;
		 
	vector<Point> p(N) ;
	vector< pair<Point, int> > sorted ;
 
	for(int i = 0 ; i < N ; i++ ) 
	{
		readLong(p[i].x ) ;
		readLong(p[i].y ) ;
		sorted.push_back( make_pair(p[i], i ) ) ;
	}
 
 	sort(all(sorted), [&]( pair<Point,int> a, pair<Point,int> b ) 
	{
		if( a.first%b.first == 0 ) return (b.first-a.first)*(Point(0,0)-a.first ) < 0 ;
		return a.first%b.first > 0 ;	
	} ) ; 
 
	int j = -1 ;
	for(int i = 0 ; i < N ; i++ ) 
	{
	   if(!i || sorted[i-1].first%sorted[i].first != 0 ) j++ ;
	   else 
	   {
	   	canceled[ sorted[i].second ] = true ;		
	   	myId[ sorted[i].second ] = j ;
	   	continue ;
	   }
      myId[sorted[i].second ] = j ;
		num[j] = sorted[i].first.y ;
		den[j] = sorted[i].first.x ;
	}
 
   seg.n = j+1 ;
	seg.ini() ;		
 
	for(int i = 0 , nxt = 1 ; i < N ; i++, nxt++ )
	{
		if(nxt ==  N ) nxt = 0 ;
 
		int l = myId[i] , r = myId[nxt] ;
 
      if(l == r ) continue ;
		if( l > r ) swap(l,r) ;
 
      t.p1 = p[i] ;
      t.p2 = p[nxt] ;
      t.cte = ( t.p1.y*t.p2.x - t.p1.x*t.p2.y ) ;
 
		seg.addLine(l,r+1 ) ;  
 
	} 
 
 
	//Don't forget to check if there is someone in the same polar angle that mine (because, if there is, it fucks everything up )
 
	vector<int> ans ;
 
	int x = sorted[0].second ;

	int nxt = x+1 ;
	int ant = x-1 ;

	if(nxt == N ) nxt = 0 ;
	if(ant == -1 ) ant = N-1 ;

	int toAdd = 1 ;

	if( (p[nxt]-p[x] ) % (p[ant]-p[x]) > 0 ) toAdd = -1 ;

	while(true)
	{

		if( !canceled[x] && seg.qry(myId[x], p[x] ) ) ans.push_back(x) ;

		if( p[x].x == den[j] && p[x].y == num[j] ) break ; 
	
		x += toAdd ;

		if(x == N ) x = 0 ;
		if( x == -1 ) x = N-1 ;		
	}

	sort(all(ans) ) ;
 
	printf("%d\n", sz(ans ) ) ;
	for(auto e : ans ) printf("%d ", e+1 ) ;
	printf("\n") ;
 
 
}

• Subtask 1: 95 / 100