Poj 3237 tree

Poj_3237

You can use link-cut-tree or tree link splitting. To handle the negate operation, two labels, Max and Min, can be used out of the lazy tag, set max to-min and min to-max.

# Include <stdio. h> # Include < String . H> # Define Maxd 100010 # Define Maxm 200010 # Define INF 0x7fffffff Int  N, Q [maxd], first [maxd], E, next [maxm], V [maxm], W [maxm], DEP [maxd];  Struct Edge {  Int  X, Y, Z;} edge [maxd];  Struct  Splay {  Int  PRE, ls, RS, neg, key, Max, min;  Bool  Root;  Void Update (); Void Pushdown (); Void Zig ( Int ); Void Zag (Int ); Void Splay ( Int  );  Void  RENEW () {Root = True  ; Pre = Ls = rs = 0  ; Neg = 0  ;}} SP [maxd];  Int Max ( Int X,Int  Y ){  Return X> Y? X: Y ;}  Int Min ( Int X, Int  Y ){  Return X <Y? X: Y ;}  Void  Splay: Update () {max = Max (max (SP [ls]. Max, SP [RS]. max), key); min =Min (min (SP [ls]. Min, SP [RS]. min), key );}  Void Makeneg ( Int  Cur ){  If (Cur! = 0  ) {SP [cur]. neg ^ = 1 , SP [cur]. Key =- SP [cur]. Key;  Int T = SP [cur]. Max; SP [cur]. Max =-SP [cur]. Min, SP [cur]. min =- T ;}}  Void Splay: Pushdown (){  If  (NEG) {makeneg (LS), makeneg (RS); neg = 0  ;}}  Void Splay: Zig ( Int  X ){  Int Y = RS, fa = Pre; Pushdown (), SP [Y]. Pushdown (); 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; Pushdown (), SP [Y]. Pushdown (); 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 (Pushdown ();! 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, Int  Z) {v [E] = Y, W [e] = Z; next [E] = First [X], first [x] = e ++ ;}  Void  Prepare (){  Int I, j, X, rear = 0  ; SP [ 0 ]. Max =-INF, SP [ 0 ]. Min = INF; Q [rear ++] = 1  ; SP [  1 ]. RENEW (), DEP [ 1 ] = 1  ;  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, DEP [V [J] = Dep [x] + 1  ; SP [V [J]. Key = Sp [V [J]. max = Sp [V [J]. min = W [J]; Q [rear ++] = V [J] ;}}  Void Swap ( Int & X, Int &Y ){  Int  T; t = X, x = Y, y = T ;}  Void  Init (){  Int  I; memset (first, - 1 , Sizeof  (First); e = 0  ; Scanf (  "  % D  " ,& N );  For (I = 1 ; I <n; I ++ ) {Scanf (  "  % D  " , & Edge [I]. X, & edge [I]. Y ,& Edge [I]. z); add (edge [I]. x, edge [I]. y, edge [I]. z), add (edge [I]. y, edge [I]. x, edge [I]. z);} prepare ();  For (I = 1 ; I <n; I ++ )  If (DEP [edge [I]. x]>Dep [edge [I]. Y]) Swap (edge [I]. X, edge [I]. Y );}  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 ();}}  Void Change ( Int X, Int  Y) {SP [X]. splay (x); SP [X]. Key = Y; SP [X]. Update ();}  Void Negate ( Int X, Int  Y ){  Int  FY; Access (X );  For (FY = Y, y = 0 ; FY! = 0 ; Y = fy, FY = SP [Y]. PRE) {SP [FY]. splay (FY );  If (SP [FY]. Pre = 0  ) Makeneg (SP [FY]. RS), makeneg (y); SP [Sp [FY]. RS]. Root = True  ; SP [FY]. RS = Y, SP [Y]. Root = False  ; SP [FY]. Update ();}}  Void Query ( Int X, Int Y ){  Int  FY; Access (X );  For (FY = Y, y = 0 ; FY! = 0 ; Y = fy, FY = SP [Y]. PRE) {SP [FY]. splay (FY );  If (SP [FY]. Pre = 0  ) Printf (  "  % D \ n  " , Max (SP [Sp [FY]. RS]. Max, SP [Y]. max); SP [Sp [FY]. RS]. Root = True  ; SP [FY]. RS = Y, SP [Y]. Root = False  ; SP [FY]. Update ();}}  Void  Solve (){  Int  X, Y;  Char OP [ 10  ];  For  (;) {Scanf ( "  % S  "  , OP );  If (OP [ 0 ] = '  D  '  )  Break  ; Scanf (  "  % D  " , & X ,& Y ); If (OP [ 0 ] = '  C  '  ) Change (edge [X]. Y, y );  Else   If (OP [ 0 ] = '  N  '  ) Negate (x, y );  Else  Query (x, y );}} Int  Main (){  Int  T; scanf (  "  % D  " ,& T );  While (T -- ) {Init (); solve ();}  Return   0  ;}