#include <bits/stdc++.h>
#define debug printf
#define all(x) x.begin(),x.end()
#define lp(i,a,b) for(int i = a ; i< b ; i++)
#define ss second
#define ff first
#define ll long long
#define pb push_back
#define pii pair<int,int>
#define mk make_pair
const int MAX = 1e6+10 ;
const int MAXN = 1e5+10 ;
using namespace std ;
int N , T , idx ;
int X[MAXN] , Y[MAXN] , vet[MAXN] , pai[MAX] , pai_aux[MAXN] ;
int dx[8] = { 1,-1,0,0, 1,-1,1,-1 } , dy[8] = { 0,0,1,-1, -1,1, 1, -1} ;
int dx_cyclic[8] = { -1 , -1 , 0 , 1 , 1 ,1 , 0, -1 } , dy_cyclic[8] = { 0 , -1 , -1 , -1, 0 , 1 , 1 ,1 } ;
pii id[MAX] ;
bool is_full[MAX] , reachable[MAX] , marc[MAXN] ;
map< pii , int > mp ;
set<int> s ;
vector<int> ans ;
vector<int> componente[MAX] ;
// ------------------------------------------------
bool cmp_maior_x( int i , int j ) { return X[i] > X[j] ; }
bool cmp_menor_x ( int i , int j ) { return X[i] < X[j] ; }
bool cmp_maior_y(int i , int j) { return Y[i] > Y[j] ; }
bool cmp_menor_y ( int i , int j ) { return Y[i] < Y[j] ; }
int get_code(int x, int y)
{
if( mp.find( mk(x,y) ) == mp.end() ) return 0 ;
return mp.find( mk(x,y) )->ss ;
}
int find(int x)
{
if( x == pai[x] ) return x ;
return pai[x] = find( pai[x] ) ;
}
bool identify_articulation(int name)
{
int j = -1 ;
vector<int> group ;
for(int i = 0 , nx , ny ; i < 8 ; i ++ )
{
nx = X[name] + dx_cyclic[i] ;
ny = Y[name] + dy_cyclic[i] ;
if( is_full[ get_code(nx,ny) ] ) { j = i ; break ; }
}
if( j == -1 ) return false ;
int beg = -1, en = beg , times = 0 ;
for(int i = (j+1)%8 ; true ; i = (i+1)%8 )
{
if( i == ((j+1)%8) && times == 1 ) break ;
else if( i == ((j+1)%8) && times == 0 ) times ++ ;
int nx = X[name] + dx_cyclic[i] ;
int ny = Y[name] + dy_cyclic[i] ;
int c = get_code(nx,ny) ;
if( is_full[c] )
{
if( beg == -1 ) continue ;
if( beg % 2 == 1 && en == beg ) { beg = -1 ; continue ; }
group.pb( find( get_code( X[name]+dx_cyclic[beg] , Y[name]+dy_cyclic[beg] ) ) ) ;
beg = -1 ;
continue ;
}
if( beg == -1 ) beg = en = i ;
else en = i ;
}
sort(all(group) ) ;
for(int i = 1 ; i < group.size() ; i++ )
if( group[i] == group[i-1] ) return true ;
return false ;
}
bool identify_infinity(int name)
{
bool ans = false ;
for(int i = 0 ; i < 4 ; i++ )
{
int code = get_code( dx[i] + X[name] , dy[i] + Y[name] ) ;
code = find(code) ;
ans |= reachable[code] ;
}
return ans ;
}
bool check(int i) { return ( !identify_articulation(i) ) && identify_infinity(i) ; }
inline void to_change(int name)
{
for(int i = 0 ; i < 8 ; i++ )
{
int nx = X[name] + dx[i] ;
int ny = Y[name] + dy[i] ;
int code = get_code( nx, ny ) ;
if(!is_full[code]) continue ;
if( check(code) && s.find(code) == s.end() ) s.insert(code) ;
else if( !check(code) && s.find(code) != s.end() ) s.erase( s.find(code) ) ;
}
}
bool join(int a, int b, bool ok = false )
{
a = find(a) ;
b = find(b) ;
if(a==b) return false ;
if( componente[a].size() > componente[b].size() ) swap( a , b );
pai[a] = b ;
reachable[b] |= reachable[a] ;
for( int i : componente[a] )
{
componente[b].pb(i) ;
if( ok ) to_change(i) ;
}
componente[a].clear() ;
return true ;
}
int find_aux(int x)
{
if( x == pai_aux[x] ) return x ;
return pai_aux[x] = find_aux( pai_aux[x] ) ;
}
inline void join_aux(int a, int b)
{
a = find_aux(a) ;
b = find_aux(b) ;
if( rand() % 2 ) swap(a,b) ;
pai_aux[a] = b ;
}
int main()
{
scanf("%d%d", &N , &T ) ;
lp(i,1,N+1)
{
scanf("%d%d", &X[i] , &Y[i]) ;
mp.insert( mk( mk( X[i] , Y[i] ) , i ) ) ;
is_full[i] = true ;
vet[i] = pai_aux[i] = i ;
}
idx = N ;
lp(i,1,N+1)
{
for(int j = 0 ; j < 8 ; j++ )
{
int nx = dx[j] + X[i] ;
int ny = dy[j] + Y[i] ;
if( mp.find( mk(nx,ny) ) == mp.end() ) mp.insert( mk( mk(nx,ny) , ++idx ) ) ;
if( is_full[ get_code(nx,ny) ] ) join_aux( i , get_code(nx,ny) ) ;
}
}
lp(i,2,N+1)
if( find_aux(i) != find_aux(1) ) { printf("NO\n") ; return 0 ; }
for(auto p : mp )
{
pai[ p.ss ] = p.ss ;
componente[p.ss].pb( p.ss ) ;
}
// Get reachability to inifinity -----------
sort( vet+1, vet+1+N, cmp_menor_x ) ;
for(int i = 1 ; i <= N ; i++ )
{
if( X[ vet[i] ] > X[ vet[1] ] ) break ;
int code = get_code( X[ vet[i] ] - 1 , Y[ vet[i] ] ) ;
reachable[ code ] = true ;
}
sort( vet+1, vet+1+N, cmp_maior_x ) ;
for(int i = 1 ; i <= N ; i++ )
{
if( X[ vet[i] ] < X[ vet[1] ] ) break ;
int code = get_code( X[ vet[i] ] + 1 , Y[ vet[i] ] ) ;
reachable[code] = true ;
}
sort( vet+1, vet+1+N, cmp_menor_y ) ;
lp(i,1,N+1)
{
if( Y[ vet[i] ] > Y[ vet[1] ] ) break ;
int code = get_code(X[ vet[i] ] , Y[ vet[i] ] - 1 ) ;
reachable[code] = true ;
}
sort( vet+1, vet+1+N , cmp_maior_y ) ;
lp(i,1,N+1)
{
if( Y[ vet[i] ] < Y[ vet[1] ] ) break ;
int code = get_code( X[ vet[i] ] , Y[ vet[i] ] + 1 ) ;
reachable[code] = true ;
}
// ---------------------------------------------
for(auto p : mp )
{
if( is_full[p.ss] ) continue ;
for(int i = 0 , nx , ny ; i < 4 ; i++ )
{
nx = dx[i] + p.ff.ff ;
ny = dy[i] + p.ff.ss ;
if( get_code(nx,ny) == 0 || is_full[ get_code(nx,ny) ] ) continue ;
join( get_code(nx,ny) , p.ss ) ;
}
}
lp(i,1,N+1)
if( check(i) ) s.insert(i) ;
while( s.size() > 0 )
{
int best_id = *( prev( s.end() ) ) ;
s.erase( prev(s.end() ) ) ;
ans.pb( best_id ) ;
is_full[best_id] = false ;
for(int i = 0 , nx , ny ; i < 4 ; i++ )
{
nx = dx[i] + X[best_id] ;
ny = dy[i] + Y[ best_id ] ;
int code = get_code( nx,ny ) ;
if( is_full[ code ] ) continue ;
join( code, best_id, true ) ;
}
to_change(best_id) ;
}
printf("YES\n") ;
reverse(all(ans)) ;
for(int i : ans ) printf("%d\n" , i ) ;
}
Compilation message
skyscrapers.cpp: In function 'bool identify_articulation(int)':
skyscrapers.cpp:96:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 1 ; i < group.size() ; i++ )
~~^~~~~~~~~~~~~~
skyscrapers.cpp: In function 'int main()':
skyscrapers.cpp:182:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &N , &T ) ;
~~~~~^~~~~~~~~~~~~~~~~~
skyscrapers.cpp:185:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &X[i] , &Y[i]) ;
~~~~~^~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
22 ms |
23808 KB |
ans=YES N=1 |
2 |
Correct |
18 ms |
23808 KB |
ans=YES N=4 |
3 |
Correct |
18 ms |
23808 KB |
ans=NO N=4 |
4 |
Correct |
17 ms |
23808 KB |
ans=YES N=5 |
5 |
Correct |
17 ms |
23808 KB |
ans=YES N=9 |
6 |
Correct |
17 ms |
23808 KB |
ans=YES N=5 |
7 |
Correct |
17 ms |
23808 KB |
ans=NO N=9 |
8 |
Correct |
17 ms |
23808 KB |
ans=NO N=10 |
9 |
Correct |
17 ms |
23808 KB |
ans=YES N=10 |
10 |
Correct |
17 ms |
23808 KB |
ans=YES N=10 |
11 |
Correct |
17 ms |
23808 KB |
ans=YES N=10 |
12 |
Correct |
18 ms |
23912 KB |
ans=YES N=9 |
13 |
Correct |
17 ms |
23936 KB |
ans=YES N=9 |
14 |
Correct |
17 ms |
23808 KB |
ans=YES N=8 |
15 |
Correct |
17 ms |
23936 KB |
ans=YES N=8 |
16 |
Correct |
17 ms |
23808 KB |
ans=NO N=2 |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
22 ms |
23808 KB |
ans=YES N=1 |
2 |
Correct |
18 ms |
23808 KB |
ans=YES N=4 |
3 |
Correct |
18 ms |
23808 KB |
ans=NO N=4 |
4 |
Correct |
17 ms |
23808 KB |
ans=YES N=5 |
5 |
Correct |
17 ms |
23808 KB |
ans=YES N=9 |
6 |
Correct |
17 ms |
23808 KB |
ans=YES N=5 |
7 |
Correct |
17 ms |
23808 KB |
ans=NO N=9 |
8 |
Correct |
17 ms |
23808 KB |
ans=NO N=10 |
9 |
Correct |
17 ms |
23808 KB |
ans=YES N=10 |
10 |
Correct |
17 ms |
23808 KB |
ans=YES N=10 |
11 |
Correct |
17 ms |
23808 KB |
ans=YES N=10 |
12 |
Correct |
18 ms |
23912 KB |
ans=YES N=9 |
13 |
Correct |
17 ms |
23936 KB |
ans=YES N=9 |
14 |
Correct |
17 ms |
23808 KB |
ans=YES N=8 |
15 |
Correct |
17 ms |
23936 KB |
ans=YES N=8 |
16 |
Correct |
17 ms |
23808 KB |
ans=NO N=2 |
17 |
Correct |
18 ms |
23808 KB |
ans=YES N=17 |
18 |
Incorrect |
18 ms |
23808 KB |
Full cells must be connected |
19 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
22 ms |
23808 KB |
ans=YES N=1 |
2 |
Correct |
18 ms |
23808 KB |
ans=YES N=4 |
3 |
Correct |
18 ms |
23808 KB |
ans=NO N=4 |
4 |
Correct |
17 ms |
23808 KB |
ans=YES N=5 |
5 |
Correct |
17 ms |
23808 KB |
ans=YES N=9 |
6 |
Correct |
17 ms |
23808 KB |
ans=YES N=5 |
7 |
Correct |
17 ms |
23808 KB |
ans=NO N=9 |
8 |
Correct |
17 ms |
23808 KB |
ans=NO N=10 |
9 |
Correct |
17 ms |
23808 KB |
ans=YES N=10 |
10 |
Correct |
17 ms |
23808 KB |
ans=YES N=10 |
11 |
Correct |
17 ms |
23808 KB |
ans=YES N=10 |
12 |
Correct |
18 ms |
23912 KB |
ans=YES N=9 |
13 |
Correct |
17 ms |
23936 KB |
ans=YES N=9 |
14 |
Correct |
17 ms |
23808 KB |
ans=YES N=8 |
15 |
Correct |
17 ms |
23936 KB |
ans=YES N=8 |
16 |
Correct |
17 ms |
23808 KB |
ans=NO N=2 |
17 |
Correct |
18 ms |
23808 KB |
ans=YES N=17 |
18 |
Incorrect |
18 ms |
23808 KB |
Full cells must be connected |
19 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
26 ms |
25080 KB |
ans=NO N=1934 |
2 |
Correct |
24 ms |
24192 KB |
ans=NO N=1965 |
3 |
Incorrect |
64 ms |
24192 KB |
Full cells must be connected |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
22 ms |
23808 KB |
ans=YES N=1 |
2 |
Correct |
18 ms |
23808 KB |
ans=YES N=4 |
3 |
Correct |
18 ms |
23808 KB |
ans=NO N=4 |
4 |
Correct |
17 ms |
23808 KB |
ans=YES N=5 |
5 |
Correct |
17 ms |
23808 KB |
ans=YES N=9 |
6 |
Correct |
17 ms |
23808 KB |
ans=YES N=5 |
7 |
Correct |
17 ms |
23808 KB |
ans=NO N=9 |
8 |
Correct |
17 ms |
23808 KB |
ans=NO N=10 |
9 |
Correct |
17 ms |
23808 KB |
ans=YES N=10 |
10 |
Correct |
17 ms |
23808 KB |
ans=YES N=10 |
11 |
Correct |
17 ms |
23808 KB |
ans=YES N=10 |
12 |
Correct |
18 ms |
23912 KB |
ans=YES N=9 |
13 |
Correct |
17 ms |
23936 KB |
ans=YES N=9 |
14 |
Correct |
17 ms |
23808 KB |
ans=YES N=8 |
15 |
Correct |
17 ms |
23936 KB |
ans=YES N=8 |
16 |
Correct |
17 ms |
23808 KB |
ans=NO N=2 |
17 |
Correct |
18 ms |
23808 KB |
ans=YES N=17 |
18 |
Incorrect |
18 ms |
23808 KB |
Full cells must be connected |
19 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
368 ms |
31916 KB |
ans=NO N=66151 |
2 |
Correct |
475 ms |
53624 KB |
ans=NO N=64333 |
3 |
Incorrect |
2529 ms |
34280 KB |
Full cells must be connected |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
26 ms |
25080 KB |
ans=NO N=1934 |
2 |
Correct |
24 ms |
24192 KB |
ans=NO N=1965 |
3 |
Incorrect |
64 ms |
24192 KB |
Full cells must be connected |
4 |
Halted |
0 ms |
0 KB |
- |