Spoj 2798 query on a tree again!

Spoj_2798

If you use link-cut-tree to write data, you only need to maintain the col (node color) and sum (number of black nodes in the subtree) labels. During the dyeing process, the corresponding node splay is added to the root node and then modified. The access (v) operation is performed first during the query, and then the root of the splay is searched recursively, if the sum value of the root node is 0,-1 is output.

# Include <stdio. h> # Include < String . H> # Define Maxd 100010 # Define Maxm 200010 Int  N, Q, Q [maxd], first [maxd], E, next [maxm], V [maxm];  Struct  Splay { Int  PRE, ls, RS, Col, sum;  Bool  Root;  Void Update (); Void Zig ( Int ); Void Zag ( Int ); Void Splay ( Int  );  Void  RENEW () {Root =True  ; Pre = Ls = rs = 0  ; Col = 0 , Sum = 0  ;}} SP [maxd];  Void  Splay: Update () {sum = Sp [ls]. Sum + SP [RS]. Sum + Col ;}  Void Splay: Zig ( Int  X ){  Int Y = RS, fa =Pre; RS = Sp [Y]. ls, SP [RS]. Pre = X; SP [Y]. ls = X, pre = Y; SP [Y]. Pre = Fa;  If  (Root) Root = False , SP [Y]. Root = True  ;  Else  SP [fa]. RS = X? SP [fa]. rs = Y: SP [fa]. ls = Y; Update ();}  Void Splay: zag (Int  X ){  Int Y = ls, fa = Pre; LS = Sp [Y]. RS, SP [ls]. Pre = X; SP [Y]. RS = X, pre = Y; SP [Y]. Pre = Fa;  If  (Root) Root = False , SP [Y]. Root = True  ;  Else  SP [fa]. RS = X? SP [fa]. rs = Y: SP [fa]. ls = Y; Update ();}  Void Splay: splay ( Int  X ){  Int  Y, Z;  For (;! Root;) {Y = Pre;  If  (SP [Y]. Root) SP [Y]. RS = X? SP [Y]. Zig (y): SP [Y]. Zag (y );  Else {Z = SP [Y]. Pre;  If (SP [Z]. rs = Y ){  If (SP [Y]. rs = X) SP [Z]. Zig (z), SP [Y]. Zig (y );  Else  SP [Y]. Zag (Y), SP [Z]. Zig (z );}  Else  {  If (SP [Y]. ls =X) SP [Z]. Zag (z), SP [Y]. Zag (y );  Else  SP [Y]. Zig (Y), SP [Z]. Zag (z) ;}} Update ();}  Void Add ( Int X, Int  Y) {v [E] = Y; next [E] = First [X], first [x] = e ++ ;}  Void  Prepare (){  Int I, j, X, rear =0  ; SP [  0 ]. Sum = 0  ; Q [rear ++] = 1  ; SP [  1  ]. RENEW ();  For (I = 0 ; I <rear; I ++ ) {X = Q [I];  For (J = first [X]; J! =- 1 ; J = Next [J])  If (V [J]! = SP [X]. PRE) {SP [V [J]. RENEW (), SP [V [J]. Pre = X; Q [rear ++] = V [J] ;}}  Void  Init (){  Int  I, X, Y; memset (first, - 1 , Sizeof  (First); e =0  ;  For (I = 1 ; I <n; I ++ ) {Scanf (  "  % D  " , & X ,& Y); add (x, y), add (Y, x);} prepare ();}  Void Change ( Int  X) {SP [X]. splay (x); SP [X]. Col ^ = 1  ; SP [X]. Update ();} Void Access ( Int  X ){  Int  FX;  For (FX = x, x = 0 ; FX! = 0 ; X = FX, FX = SP [X]. PRE) {SP [FX]. splay (FX); SP [Sp [FX]. RS]. Root = True  ; SP [FX]. RS = X, SP [X]. Root = False  ; SP [FX]. Update ();}} Int Search ( Int  Cur ){  If (SP [Sp [cur]. ls]. Sum! = 0  )  Return  Search (SP [cur]. ls );  Else   If  (SP [cur]. col)  Return  Cur;  Else          Return Search (SP [cur]. RS );}  Void Ask ( Int  X ){  Int  Y; Access (X );  For (Y = x ;! SP [Y]. root; y = SP [Y]. PRE );  If (SP [Y]. Sum = 0  ) Printf (  "  -1 \ n  "  ); Else  Printf (  "  % D \ n  "  , Search (y ));}  Void  Solve (){  Int  I, op, X;  For (I = 0 ; I <q; I ++ ) {Scanf (  "  % D  " , & OP ,& X );  If (OP = 0  ) Change (X );  Else  Ask (x );}}  Int  Main (){  While (Scanf ( "  % D  " , & N, & Q) = 2  ) {Init (); solve ();} Return   0  ;}