#include <bits/stdc++.h>
template <class T = int> inline T readInt();
inline double readDouble();
inline int readUInt();
inline int readChar(); // first non-blank character
inline void readWord( char *s );
inline bool readLine( char *s ); // do not save '\n'
inline bool isEof();
inline int getChar();
inline int peekChar();
inline bool seekEof();
inline void skipBlanks();
template <class T> inline void writeInt( T x, char end = 0, int len = -1 );
inline void writeChar( int x );
inline void writeWord( const char *s );
inline void writeDouble( double x, int len = 0 );
inline void flush();
static struct buffer_flusher_t {
~buffer_flusher_t() {
flush();
}
} buffer_flusher;
/** Read */
static const int buf_size = 4096;
static unsigned char buf[buf_size];
static int buf_len = 0, buf_pos = 0;
inline bool isEof() {
if (buf_pos == buf_len) {
buf_pos = 0, buf_len = fread(buf, 1, buf_size, stdin);
if (buf_pos == buf_len)
return 1;
}
return 0;
}
inline int getChar() {
return isEof() ? -1 : buf[buf_pos++];
}
inline int peekChar() {
return isEof() ? -1 : buf[buf_pos];
}
inline bool seekEof() {
int c;
while ((c = peekChar()) != -1 && c <= 32)
buf_pos++;
return c == -1;
}
inline void skipBlanks() {
while (!isEof() && buf[buf_pos] <= 32U)
buf_pos++;
}
inline int readChar() {
int c = getChar();
while (c != -1 && c <= 32)
c = getChar();
return c;
}
inline int readUInt() {
int c = readChar(), x = 0;
while ('0' <= c && c <= '9')
x = x * 10 + c - '0', c = getChar();
return x;
}
template <class T>
inline T readInt() {
int s = 1, c = readChar();
T x = 0;
if (c == '-')
s = -1, c = getChar();
else if (c == '+')
c = getChar();
while ('0' <= c && c <= '9')
x = x * 10 + c - '0', c = getChar();
return s == 1 ? x : -x;
}
inline double readDouble() {
int s = 1, c = readChar();
double x = 0;
if (c == '-')
s = -1, c = getChar();
while ('0' <= c && c <= '9')
x = x * 10 + c - '0', c = getChar();
if (c == '.') {
c = getChar();
double coef = 1;
while ('0' <= c && c <= '9')
x += (c - '0') * (coef *= 1e-1), c = getChar();
}
return s == 1 ? x : -x;
}
inline void readWord( char *s ) {
int c = readChar();
while (c > 32)
*s++ = c, c = getChar();
*s = 0;
}
inline bool readLine( char *s ) {
int c = getChar();
while (c != '\n' && c != -1)
*s++ = c, c = getChar();
*s = 0;
return c != -1;
}
/** Write */
static int write_buf_pos = 0;
static char write_buf[buf_size];
inline void writeChar( int x ) {
if (write_buf_pos == buf_size)
fwrite(write_buf, 1, buf_size, stdout), write_buf_pos = 0;
write_buf[write_buf_pos++] = x;
}
inline void flush() {
if (write_buf_pos) {
fwrite(write_buf, 1, write_buf_pos, stdout), write_buf_pos = 0;
fflush(stdout);
}
}
template <class T>
inline void writeInt( T x, char end, int output_len ) {
if (x < 0)
writeChar('-'), x = -x;
char s[24];
int n = 0;
while (x || !n)
s[n++] = '0' + x % 10, x /= 10;
while (n < output_len)
s[n++] = '0';
while (n--)
writeChar(s[n]);
if (end)
writeChar(end);
}
inline void writeWord( const char *s ) {
while (*s)
writeChar(*s++);
}
inline void writeDouble( double x, int output_len ) {
if (x < 0)
writeChar('-'), x = -x;
int t = (int)x;
writeInt(t), x -= t;
writeChar('.');
for (int i = output_len - 1; i > 0; i--) {
x *= 10;
t = std::min(9, (int)x);
writeChar('0' + t), x -= t;
}
x *= 10;
t = std::min(9, (int)(x + 0.5));
writeChar('0' + t);
}
#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()
{
N = readInt() ;
vector<Point> p(N) ;
vector< pair<Point, int> > sorted ;
for(int i = 0 ; i < N ; i++ )
{
p[i].x = readInt() ;
p[i].y = readInt() ;
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") ;
}
| # |
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 |
12 ms |
16436 KB |
Output is correct |
| 5 |
Correct |
14 ms |
16872 KB |
Output is correct |
| 6 |
Correct |
14 ms |
16872 KB |
Output is correct |
| 7 |
Correct |
19 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 |
14 ms |
17000 KB |
Output is correct |
| 12 |
Correct |
15 ms |
17600 KB |
Output is correct |
| 13 |
Correct |
25 ms |
18404 KB |
Output is correct |
| 14 |
Correct |
22 ms |
19168 KB |
Output is correct |
| 15 |
Correct |
24 ms |
19936 KB |
Output is correct |
| 16 |
Correct |
42 ms |
23516 KB |
Output is correct |
| 17 |
Correct |
81 ms |
23516 KB |
Output is correct |
| 18 |
Correct |
71 ms |
31060 KB |
Output is correct |
| 19 |
Correct |
72 ms |
30932 KB |
Output is correct |
| 20 |
Execution timed out |
177 ms |
30928 KB |
Time limit exceeded |
