树链剖分

#include<cstdio>#include<cstring>#include<iostream>using namespace std;const int N=1e5;const int M=N;struct Edge {    int v,next;    Edge(int v=-1,int next=-1):v(v),next(next){}}e[M*2];int head[N],total;void init(){    memset(head,-1,sizeof(head));total=0;}void adde(int u,int v){    e[total]=Edge(v,head[u]);head[u]=total++;}int dep[N],sz[N],fa[N],son[N];void getson(int u,int f){///重儿子    dep[u]=dep[f]+1;sz[u]=1;fa[u]=f;son[u]=-1;    for(int i=head[u];i!=-1;i=e[i].next){        int v=e[i].v;        if(v==f)continue;        getson(v,u);        sz[u]+=sz[v];        if(son[u]==-1||sz[son[u]]<sz[v])son[u]=v;    }}int top[N],p[N],fp[N],pos;void getpos(int u,int clo){////重链在p中连续    top[u]=clo;    p[u]=++pos;    fp[pos]=u;    if(son[u]==-1)return ;    getpos(son[u],clo);    for(int i=head[u];i!=-1;i=e[i].next){        int v=e[i].v;        if(v!=son[u]&&v!=fa[u]){            getpos(v,v);        }    }}////////seg_tree;void lca(int u,int v){    int fu=top[u],fv=top[v];    while(fu!=fv){        if(dep[fu]<dep[fv]){            swap(fu,fv);            swap(u,v);        }        ///L=p[fu],R=p[u];update(1,pos,1);        u=fa[fu];fu=top[u];    }    if(dep[u]>dep[v])swap(u,v);    ////L=p[u],R=p[v];update(1,pos,1);}void solve(){    pos=0;    dep[0]=0;    getson(1,0);    getpos(1,1);}int main(){    return 0;}