Code:
#include <cstdio> //SDOI2010 染色 #include <algorithm> #include <cstring> #include <string> using namespace std; void setIO(string a) { freopen((a+".in").c_str(),"r",stdin); } struct LCT { #define maxn 200000 #define lson(x) ch[x][0] #define rson(x) ch[x][1] int ch[maxn][2],f[maxn],siz[maxn]; int val[maxn],left[maxn],right[maxn]; int tag[maxn]; int sta[maxn]; int lazy[maxn]; int isRoot(int x) { return !(ch[f[x]][0]==x||ch[f[x]][1]==x); } int get(int x) { return ch[f[x]][1]==x; } void update(int x,int c) { if(!x)return; val[x]=left[x]=right[x]=c,siz[x]=1,lazy[x]=c; } void pushup(int x) { if(!x) return; siz[x]=siz[lson(x)]+siz[rson(x)]+1; left[x]=lson(x)?left[lson(x)]:val[x]; right[x]=rson(x)?right[rson(x)]:val[x]; if(right[lson(x)]==val[x]) siz[x]-=1; if(left[rson(x)]==val[x]) siz[x]-=1; } void mark(int x) { if(!x) return; swap(ch[x][0],ch[x][1]); swap(left[x],right[x]); tag[x]^=1; } void pushdown(int x) { if(lazy[x]) update(lson(x),lazy[x]),update(rson(x),lazy[x]),lazy[x]=0; if(tag[x]) mark(lson(x)),mark(rson(x)),tag[x]=0; } void rotate(int x) { int old=f[x], fold=f[old], which=get(x); if(!isRoot(old)) ch[fold][ch[fold][1]==old]=x; ch[old][which]=ch[x][which^1],f[ch[old][which]]=old; ch[x][which^1]=old,f[old]=x,f[x]=fold; pushup(old),pushup(x); } void splay(int x) { int v=0,u=x; sta[++v]=u; while(!isRoot(u)) sta[++v]=f[u],u=f[u]; while(v) pushdown(sta[v--]); u=f[u]; for(int fa;(fa=f[x])!=u;rotate(x)) if(f[fa]!=u) rotate(get(fa)==get(x)?fa:x); } void Access(int x) { for(int y=0;x;y=x,x=f[x]) splay(x), ch[x][1]=y, pushup(x); } void makeRoot(int x) { Access(x), splay(x), mark(x); } void link(int a,int b) { makeRoot(a), f[a]=b; } void split(int a,int b) { makeRoot(a), Access(b), splay(b); } }tree; int main() { //setIO("input"); int n,m; scanf("%d%d",&n,&m); for(int i=1;i<=n;++i) scanf("%d",&tree.val[i]),tree.left[i]=tree.right[i]=tree.val[i],tree.siz[i]=1; for(int i=1;i<n;++i) { int a,b; scanf("%d%d",&a,&b); tree.link(a,b); } while(m--) { int x,y,z; char opt[20]; scanf("%s",opt); switch(opt[0]) { case 'C': { scanf("%d%d%d",&x,&y,&z); tree.split(x,y),tree.update(y,z); break; } case 'Q': { scanf("%d%d",&x,&y); tree.split(x,y), printf("%d ",tree.siz[y]); break; } } } return 0; }