[SDOI2011]染色

给定一棵有n(n<=100000)个节点的无根树和m个操作，操作有2类：1、将节点a到节点b路径上所有点都染成颜色c；2、询问节点a到节点n路径上的颜色段数量（连续相同颜色被认为是同一段），如“112221”由3段组成：“11”、“222”和“1”。请你写一个程序依次完成这m个操作。

维护稍微麻烦一点的动态树，记得每次Splay之前Relax一下，把标记push下来

//Lib#include<cstdio>#include<cstring>#include<cstdlib>#include<cmath>#include<ctime>#include<iostream>#include<algorithm>#include<vector>#include<string>#include<queue>using namespace std;//Macro#define rep(i,a,b) for(int i=a,tt=b;i<=tt;++i)#define rrep(i,a,b) for(int i=a,tt=b;i>=tt;--i)#define erep(i,e,x) for(int i=x;i;i=e[i].next)#define irep(i,x) for(__typedef(x.begin()) i=x.begin();i!=x.end();i++)#define read() (strtol(ipos,&ipos,10))#define sqr(x) ((x)*(x))#define pb push_back#define PS system("pause");typedef long long ll;typedef pair<int,int> pii;const int oo=~0U>>1;const double inf=1e20;const double eps=1e-6;string name="",in=".in",out=".out";//Varstruct T{int LC,RC,FA,COVER,COLOR,CNT,LCR,RCR;#define lc(x) tree[x].LC#define rc(x) tree[x].RC#define fa(x) tree[x].FA#define cnt(x) tree[x].CNT#define cover(x) tree[x].COVER#define color(x) tree[x].COLOR#define lcr(x) tree[x].LCR#define rcr(x) tree[x].RCR}tree[100008];struct E{int next,node;}e[200008];int h[100008],w[100008];int n,m,tot;inline void Update(int x){if(x==0)return;if(!lc(x))lcr(x)=color(x);else lcr(x)=lcr(lc(x));if(!rc(x))rcr(x)=color(x);else rcr(x)=rcr(rc(x));cnt(x)=cnt(lc(x))+cnt(rc(x))+1;if(rcr(lc(x))==color(x))cnt(x)--;if(lcr(rc(x))==color(x))cnt(x)--;}inline void Zig(int x){int y=fa(x),z=fa(y);if(lc(z)==y)lc(z)=x;else if(rc(z)==y)rc(z)=x;fa(x)=z;fa(rc(x))=y;lc(y)=rc(x);rc(x)=y;fa(y)=x;Update(y);}inline void Zag(int x){int y=fa(x),z=fa(y);if(lc(z)==y)lc(z)=x;else if(rc(z)==y)rc(z)=x;fa(x)=z;fa(lc(x))=y;rc(y)=lc(x);lc(x)=y;fa(y)=x;Update(y);}inline bool isRoot(int x){return lc(fa(x))!=x&&rc(fa(x))!=x;}inline void Set(int x,int y){if(x==0)return;color(x)=lcr(x)=rcr(x)=cover(x)=y;cnt(x)=1;}inline void Push(int x){if(x==0)return;if(cover(x)){Set(lc(x),cover(x));Set(rc(x),cover(x));cover(x)=0;}}void Relax(int x){if(!isRoot(x))Relax(fa(x));Push(x);}void Splay(int x){Relax(x);for(int y,z;!isRoot(x);){y=fa(x),z=fa(y);if(isRoot(y))if(lc(y)==x)Zig(x);else Zag(x);elseif(lc(z)==y)if(lc(y)==x)Zig(y),Zig(x);else Zag(x),Zig(x);elseif(rc(y)==x)Zag(y),Zag(x);else Zig(x),Zag(x);}Update(x);}inline void Expose(int x){for(int y=0;x;x=fa(x)){Splay(x);rc(x)=y;Update(x);y=x;}}inline void add(int a,int b){e[++tot].next=h[a];e[tot].node=b;h[a]=tot;}void DFS(int u,int fa){color(u)=w[u];erep(i,e,h[u])if(e[i].node!=fa){DFS(e[i].node,u);fa(e[i].node)=u;}}void Init(){int a,b;scanf("%d%d",&n,&m);rep(i,1,n)scanf("%d",w+i);rep(i,1,n-1){scanf("%d%d",&a,&b);add(a,b);add(b,a);}DFS(1,0);}void Change(int x,int y,int c){Expose(y);for(y=0;x;x=fa(x)){Splay(x);if(!fa(x)){Set(rc(x),c);Push(rc(x));color(x)=c;Update(x);Set(y,c);Push(y);}rc(x)=y;Update(x);y=x;}}int Query(int x,int y){Expose(y);int cc;for(y=0;x;x=fa(x)){Splay(x);if(!fa(x)){cc=cnt(rc(x))+cnt(y)+1;if(lcr(rc(x))==color(x))cc--;if(lcr(y)==color(x))cc--;return cc;}rc(x)=y;Update(x);y=x;}}void Work(){char ch[10];int a,b,c;rep(i,1,m){scanf("%s",ch);if(ch[0]=='C')scanf("%d%d%d",&a,&b,&c),Change(a,b,c);else scanf("%d%d",&a,&b),printf("%d\n",Query(a,b));}}int main(){//freopen((name+in).c_str(),"r",stdin);//freopen((name+out).c_str(),"w",stdout);Init();Work();return 0;}