BZOJ 4448 主席树+树链剖分（在线）

为什么题解都是离线的…… （抄都没法抄）
搞一棵主席树
1 操作 新树上的当前节点设成1
2 操作 查max(i-xx-1,0)那棵树上这条路径上有多少个点是1
让你找经过了多少个点 查的时候用deep 搞出来就好了

//By SiriusRen
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
#define N 444444
#define mem(x,y) memset(x,y,sizeof(x))
int n,q,op,xx,yy,zz,first[N],v[N],next[N],tot,root,rt[N],ans;
int size[N],fa[N],son[N],deep[N],top[N],change[N],back[N],cnt;
struct Tree{int l,r,num;}tree[N*30];
void Add(int x,int y){v[tot]=y,next[tot]=first[x],first[x]=tot++;}
void add(int x,int y){Add(x,y),Add(y,x);}
void dfs(int x){
    size[x]=1;
    for(int i=first[x];~i;i=next[i])if(v[i]!=fa[x]){
        deep[v[i]]=deep[x]+1,fa[v[i]]=x,dfs(v[i]);
        size[x]+=size[v[i]];
        if(size[son[x]]<size[v[i]])son[x]=v[i];
    }
}
void dfs2(int x,int tp){
    change[x]=++cnt,back[cnt]=x;top[x]=tp;
    if(son[x])dfs2(son[x],tp);
    for(int i=first[x];~i;i=next[i])
        if(v[i]!=fa[x]&&v[i]!=son[x])dfs2(v[i],v[i]);
}
void push_up(int pos){tree[pos].num=tree[tree[pos].l].num+tree[tree[pos].r].num;}
int build(int l,int r){
    int pos=++cnt;
    if(l==r){return pos;}
    int mid=(l+r)>>1;
    tree[pos].l=build(l,mid),tree[pos].r=build(mid+1,r);
    return pos;
}
int insert(int o,int l,int r,int num){
    int pos=++cnt;tree[pos]=tree[o];
    if(l==r){tree[pos].num=1;return pos;}
    int mid=(l+r)>>1;
    if(mid>=num)tree[pos].l=insert(tree[o].l,l,mid,num);
    else tree[pos].r=insert(tree[o].r,mid+1,r,num);
    push_up(pos);return pos;
}
int query(int o,int l,int r,int L,int R){
    if(l>=L&&r<=R)return tree[o].num;
    int mid=(l+r)>>1; 
    if(mid<L)return query(tree[o].r,mid+1,r,L,R);
    else if(mid>=R)return query(tree[o].l,l,mid,L,R);
    else return query(tree[o].l,l,mid,L,R)+query(tree[o].r,mid+1,r,L,R);
}
int find(int x,int y,int wei){
    int fx=top[x],fy=top[y],temp=0;
    while(fx!=fy){
        if(deep[fx]<deep[fy])swap(x,y),swap(fx,fy);
        temp+=query(rt[wei],1,n,change[fx],change[x]),ans+=deep[x]-deep[fx]+1;
        x=fa[fx],fx=top[x];
    }
    if(deep[x]<deep[y])swap(x,y);
    ans+=deep[x]-deep[y]+1;
    return temp+query(rt[wei],1,n,change[y],change[x]);
}
int main(){
    mem(first,-1);scanf("%d",&n);
    for(int i=1;i<=n;i++){
        scanf("%d",&fa[i]);
        if(!fa[i])root=i;else add(i,fa[i]);
    }
    dfs(root),dfs2(root,root),cnt=0,rt[0]=build(1,n);
    scanf("%d",&q);
    for(int i=1;i<=q;i++){
        scanf("%d",&op);
        if(op==1){
            rt[i]=rt[i-1],ans=0;
            scanf("%d%d%d",&xx,&yy,&zz);
            zz=max(i-zz-1,0);
            printf("%d %d
",ans,find(xx,yy,zz));
        }
        else scanf("%d",&xx),rt[i]=insert(rt[i-1],1,n,change[xx]);
    }
}