#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+1 ;
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] ;
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++ ;
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 ;
for(int i=0 ; i < N ; i++ )
{
if(i && sorted[i-1].first%sorted[i].first == 0 ) continue ;
if(seg.qry(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") ;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
9 ms |
15980 KB |
Output is correct |
| 2 |
Correct |
9 ms |
16108 KB |
Output is correct |
| 3 |
Correct |
10 ms |
16364 KB |
Output is correct |
| 4 |
Correct |
11 ms |
16364 KB |
Output is correct |
| 5 |
Correct |
14 ms |
16872 KB |
Output is correct |
| 6 |
Correct |
15 ms |
16872 KB |
Output is correct |
| 7 |
Correct |
20 ms |
17636 KB |
Output is correct |
| 8 |
Correct |
13 ms |
16688 KB |
Output is correct |
| 9 |
Correct |
13 ms |
16744 KB |
Output is correct |
| 10 |
Correct |
14 ms |
16872 KB |
Output is correct |
| 11 |
Correct |
16 ms |
17000 KB |
Output is correct |
| 12 |
Correct |
16 ms |
17636 KB |
Output is correct |
| 13 |
Correct |
26 ms |
18404 KB |
Output is correct |
| 14 |
Correct |
25 ms |
19168 KB |
Output is correct |
| 15 |
Correct |
26 ms |
19808 KB |
Output is correct |
| 16 |
Correct |
43 ms |
23516 KB |
Output is correct |
| 17 |
Correct |
77 ms |
23680 KB |
Output is correct |
| 18 |
Correct |
81 ms |
30928 KB |
Output is correct |
| 19 |
Correct |
79 ms |
30928 KB |
Output is correct |
| 20 |
Execution timed out |
174 ms |
30928 KB |
Time limit exceeded |
