【HDU】1890 Robotic Sort 翻转区间【splay】

传送门：【HDU】1890 Robotic Sort

题目分析：嗷，一个早上终于写出来了，总之splay还是不熟练啊，调死了。这次学到了几个操作，比如直接旋转出一个区间，这个操作要注意需要两个虚节点，最左端一个，最右端一个。23333写出来的感觉真爽啊~

感觉本题没什么好讲的。。。不会splay就去找资料学好了，splay对我来说目前只是调试烦。。。

代码如下：

/*void clear ()                       清空所有信息待下一次使用Node* newnode ( int v , Node* fa )  新建节点void rotate ( Node* o , int d )     旋转void splay ( Node* o , Node* t )    将o旋转到t的下面void select ( int k , Node* t )     找到第k个数并将其旋转到t的下面Node* get ( int l , int r )         找到区间[l,r]，令root = l - 1,root -> ch[1] = r + 1void reverse ( int l , int r )      翻转区间[l,r]*/#include <cstdio>#include <cstring>#include <algorithm>using namespace std ;#define REP( i , a , b ) for ( int i = a ; i < b ; ++ i )#define FOR( i , a , b ) for ( int i = a ; i <= b ; ++ i )#define REV( i , a , b ) for ( int i = a ; i >= b ; -- i )#define CLR( a , x ) memset ( a , x , sizeof a )const int MAXN = 100005 ;const int INF = 0x3f3f3f3f ;struct Node {Node* ch[2] ;Node* fa ;int v ;int s ;int rev ;int minv ;Node () {s = 0 ;v = minv = INF ;rev = 0 ;}int cmp ( int x ) {return x == v ? -1 : ( x < v ? 0 : 1 ) ;}void pushup () {s = 1 + ch[0] -> s + ch[1] -> s ;minv = min ( v , min ( ch[0] -> minv , ch[1] -> minv ) ) ;}void pushdown () ;} Tnull , *null = &Tnull ;void Node :: pushdown () {if ( !rev ) return ;rev = 0 ;swap ( ch[0] , ch[1] ) ;if ( ch[0] != null ) ch[0] -> rev ^= 1 ;if ( ch[1] != null ) ch[1] -> rev ^= 1 ;}struct Num {int x , idx ;} ;int cmpx ( const Num& a , const Num& b ) {return a.x < b.x ;}int cmpidx ( const Num& a , const Num& b ) {return a.idx < b.idx ;}struct Splay {Node node[MAXN] ;Node* root ;Node* cur ;Num num[MAXN] ;int n ;Splay () {cur = node ;root = null ;}void clear () {cur = node ;root = null ;}Node* newnode ( int v , Node* fa ) {cur -> ch[0] = cur -> ch[1] = null ;cur -> fa = fa ;cur -> s = 1 ;cur -> v = cur -> minv = v ;cur -> rev = 0 ;return cur ++ ;}void rotate ( Node* o , int d ) {Node* p = o -> fa ;p -> pushdown () ;o -> pushdown () ;p -> ch[d ^ 1] = o -> ch[d] ;o -> ch[d] -> fa = p ;o -> fa = p -> fa ;if ( p -> fa != null ) {if ( p == p -> fa -> ch[0] ) p -> fa -> ch[0] = o ;else p -> fa -> ch[1] = o ;}o -> ch[d] = p ;p -> fa = o ;p -> pushup () ;if ( root == p ) root = o ;}void splay ( Node* o , Node* t ) {while ( o -> fa != t ) {Node* p = o -> fa ;Node* gp = p -> fa ;if ( gp == t ) {if ( o == p -> ch[0] ) rotate ( o , 1 ) ;else rotate ( o , 0 ) ;} else {if ( p == gp -> ch[0] ) {if ( o == p -> ch[0] ) rotate ( p , 1 ) , rotate ( o , 1 ) ;else rotate ( o , 0 ) , rotate ( o , 1 ) ;} else {if ( o == p -> ch[1] ) rotate ( p , 0 ) , rotate ( o , 0 ) ;else rotate ( o , 1 ) , rotate ( o , 0 ) ;}}}o -> pushup () ;}void select ( int k , Node* t ) {Node* o = root ;++ k ;//空出虚拟节点的位置while ( o != null ) {o -> pushdown () ;int s = o -> ch[0] -> s ;if ( k == s + 1 ) break ;if ( k <= s ) o = o -> ch[0] ;else {k -= s + 1 ;o = o -> ch[1] ;}}splay ( o , t ) ;}Node* get ( int l , int r ) {select ( l - 1 , null ) ;select ( r + 1 , root ) ;return root -> ch[1] -> ch[0] ;}void reverse ( int l , int r ) {Node* o = get ( l , r ) ;o -> rev ^= 1 ;splay ( o , null ) ;}int find ( int x ) {Node* o = root ;int k = 0 ;while ( o != null ) {o -> pushdown () ;if ( o -> v == x ) {k += o -> ch[0] -> s + 1 ;break ;}if ( o -> ch[1] -> minv > x ) o = o -> ch[0] ;else {k += o -> ch[0] -> s + 1 ;o = o -> ch[1] ;}}return k - 1 ;}void init () {clear () ;FOR ( i , 0 , n + 1 ) {Node* o = newnode ( num[i].x , null ) ;o -> ch[0] = root ;root -> fa = o ;root = o ;root -> pushup () ;}}void solve () {num[0].x = num[n + 1].x = INF ;FOR ( i , 1 , n ) {scanf ( "%d" , &num[i].x ) ;num[i].idx = i ;}stable_sort ( num + 1 , num + n + 1 , cmpx ) ;FOR ( i , 1 , n ) num[i].x = i ;sort ( num + 1 , num + n + 1 , cmpidx ) ;init () ;FOR ( i , 1 , n ) {int k = find ( i ) ;printf ( "%d%c" , k , i < n ? ' ' : '\n' ) ;reverse ( i , k ) ;}}} T ;int main () {while ( ~scanf ( "%d" , &T.n ) && T.n )T.solve () ;return 0 ;}