BZOJ1103【树状数组】

/* I will wait for you */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<ctime>
#include<algorithm>
#include<iostream>
#include<fstream>
#include<vector>
#include<queue>
#include<deque>
#include<set>
#include<map>
#include<string>
#define make make_pair
#define fi first
#define se second

using namespace std;

typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int,int> PII;

const int maxn=250010;
const int maxm=1010;
const int maxs=26;
const int INF=1<<29;
const int P=1000000007;
const double error=1e-9;

struct edge{ int v,next; }e[2*maxn];

int cnt,clo,m,n,s[2*maxn],head[2*maxn],size[maxn],deep[maxn],su[maxn],q[maxn],fa[maxn],vis[maxn];

void add(int u,int v)
{
e[cnt]=(edge){v,head[u]},head[u]=cnt++;
e[cnt]=(edge){u,head[v]},head[v]=cnt++;
}

void ins(int x,int c)
{
for(;x<maxn;x+=x&(-x)) s[x]+=c;
}

int ask(int x)
{
int ans=0;for(;x;x-=x&(-x)) ans+=s[x];return ans;
}

void dfs()
{
int top=1;q[top]=1;
while(top)
{
int u=q[top--],p=fa[u];
if(!vis[u])
{
size[u]=vis[u]=1,su[u]=++clo,q[++top]=u;
for(int i=head[u],v;i!=-1;i=e[i].next)
if((v=e[i].v)!=p) deep[v]=deep[u]+1,fa[v]=u,q[++top]=v;
}
else
{
for(int i=head[u],v;i!=-1;i=e[i].next)
if((v=e[i].v)!=p) size[u]+=size[v];
}
}
}

int main()
{
scanf("%d",&n);memset(head,-1,sizeof(head));
for(int i=1,u,v;i<n;i++) scanf("%d%d",&u,&v),add(u,v);

dfs();
for(int i=1;i<=n;i++) ins(su[i],deep[i]),ins(su[i]+1,-deep[i]);

scanf("%d",&m);
for(int i=1,u,v;i<n+m;i++)
{
char t[10];scanf("%s",s);
if(s[0]=='W') scanf("%d",&u),printf("%d\n",ask(su[u]));
if(s[0]=='A')
{
scanf("%d%d",&u,&v);if(deep[u]<deep[v]) swap(u,v);
ins(su[u],-1),ins(su[u]+size[u],1);
}
}

return 0;
}