Submission #349543

#	Time	Username	Problem	Language	Result	Execution time	Memory
349543		CaroLinda	Printed Circuit Board (CEOI12_circuit)	C++14	75 / 100	503 ms	40016 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 ;
 
int N ;
int myId[MAX] ;
ll num[MAX], den[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 print() { printf("%lld %lld\n" , x , y) ; }
    void read() { scanf("%lld %lld", &x, &y) ; }
} ;
 
struct Line
{
	Point p1, p2 ;
 
	Line( Point p1 = Point(0,0) , Point p2 = Point(0,0) ) : p1(p1) , p2(p2) {}
	void print() 
	{
		printf("(%lld, %lld) and (%lld, %lld)\n", p1.x, p1.y, p2.x, p2.y ) ;
	}
 
}  ;
 
bool isLess(ll num1, ll den1, ll num2, ll den2 )
{
	//It doesn't happen that den < 0, because x is always positive 
 
	ll q1 = num1/den1 ;
	ll q2 = num2/den2 ;
	ll r1 = num1%den1 ;
	ll r2 = num2%den2 ;
 
	if( q1 != q2 ) return q1 < q2 ;
	if( r1 == 0 || r2 == 0 ) return r1 == 0 && r2 > 0 ;
 
	return isLess(den2, r2, den1, r1 ) ;
}
 
ll getNum( Line t, int id )
{
	return den[id] * ( t.p1.y*t.p2.x - t.p1.x*t.p2.y ) ;
}
 
ll getDen(Line t, int id )
{
	return den[id] * ( t.p1.y - t.p2.y ) - num[id] * (t.p1.x-t.p2.x ) ;
}
 
struct Seg
{
	Line tree[MAX*4] ;
	
	int m(int l, int r ) { return (l+r)>>1 ; }
 
	void addLine(int pos, int l, int r, int beg, int en, Line t )
	{
 
		if( l > en || r < beg ) return ;
		if( l >= beg && r <= en )
		{
			if( tree[pos].p1 == Point(0,0) ) return (void)(tree[pos] = t ) ; 
 
			//check if tree[pos] is less than t
			vector<bool> ok ;
 
			for(auto e : {l , r } ) 
			{
				ll num1 = getNum(tree[pos], e) ;
				ll den1 = getDen(tree[pos], e ) ;
				ll num2 = getNum(t, e ) ;
				ll den2 = getDen(t, e ) ;
				
				if(den1 < 0 ) num1 = -num1 , den1 = -den1 ;
				if( den2 < 0 ) num2 = -num2, den2 = -den2 ;
 
				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 ;
 
				ok.push_back( isLess(num1, den1, num2, den2 ) )  ;
 
			}
 
			if( !ok[0] && !ok[1] ) tree[pos] = t ;
 
			return ; 
		}
 
		addLine(pos<<1 , l , m(l,r) , beg, en, t ) ;
		addLine(pos<<1|1, m(l,r)+1, r, beg, en, t ) ;
 
	}
 
	bool qry(int pos, int l, int r, int x, Point p )
	{
 
		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( tree[pos].p1 != p && tree[pos].p2 != p && tree[pos].p1 != Point(0,0) && (val1 < 0 ) != (val2 < 0)  )
			return false ;
 
		if( l == r ) return true ;
 
		if( x <= m(l,r) ) return qry(pos<<1 , l , m(l,r), x, p ) ;
		return qry(pos<<1|1, m(l,r)+1, r, x, p ) ;
 
	}
 
	void print(int pos, int l, int r )
	{
		printf("Covering [%d,%d], there is " , l ,r ) ; tree[pos].print() ;
		if( l == r ) return ;
		print(pos<<1 , l , m(l,r) ) ;
		print(pos<<1|1, m(l,r)+1, r ) ;
	}
 
} seg ;
 
int main()
{
 
	scanf("%d", &N ) ;
 
	vector<Point> p(N) ;
	vector< pair<Point, int> > sorted ;
 
	for(int i = 0 ; i < N ; i++ ) 
	{
		p[i].read() ;
		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 ;	
	} ) ; 
 
	for(int i = 0 , j = -1 ; i < N ; i++ ) 
	{
	   if(!i || sorted[i-1].first%sorted[i].first != 0 ) j++ ;
	   		
		myId[ sorted[i].second ] = j ;
 
		num[j] = sorted[i].first.y ;
		den[j] = sorted[i].first.x ;
	}
 
	//for(int i= 0 ; i < N ; i++ ) printf("%lld %lld\n", den[i], num[i] ) ;
 
	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 ) swap(l,r) ;
 
		if(l != r ) 
			seg.addLine(1, 0 , N-1, l,r, Line( p[i], p[nxt] ) ) ;  
	} 
 
	//seg.print(1,0,N-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 ;
	for(int i=0 ; i < N ; i++ )
	{
		if(i && sorted[i-1].first%sorted[i].first == 0 ) continue ;
		if(seg.qry(1,0,N-1, myId[ sorted[i].second ] , sorted[i].first )) ans.push_back(sorted[i].second ) ;
	}
 
	sort(all(ans) ) ;
 
	printf("%d\n", sz(ans ) ) ;
	for(auto e : ans ) printf("%d ", e+1 ) ;
	printf("\n") ;
 
 
}

Compilation message (stderr)

circuit.cpp: In function 'int main()':
circuit.cpp:148:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  148 |  scanf("%d", &N ) ;
      |  ~~~~~^~~~~~~~~~~
circuit.cpp: In member function 'void Point::read()':
circuit.cpp:35:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   35 |     void read() { scanf("%lld %lld", &x, &y) ; }
      |                   ~~~~~^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 75 / 100