HDU3966.Aragorn's Story——树链剖分+树状数组（基于点权）

http://acm.split.hdu.edu.cn/showproblem.php?pid=3966

模板题贴模板
手动扩栈

#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<iostream>
#include<cstring>
#include<cstdio>
const int maxn=50010;
using namespace std;
struct node{
    int v,next;
}edges[maxn<<1];int tot,head[maxn],n;
void addedge(int u,int v){
    edges[tot].v=v;
    edges[tot].next=head[u];
    head[u]=tot++;
}
int deep[maxn],top[maxn],fa[maxn],size[maxn],p[maxn],fp[maxn],son[maxn];
int pos;
void Init(){
    tot=0;
    pos=1;
    memset(head,-1,sizeof(head));
    memset(son,-1,sizeof(son));
}
void dfs1(int u,int pre,int d){
    size[u]=1;
    fa[u]=pre;
    deep[u]=d;
    for(int i=head[u];i!=-1;i=edges[i].next){
        int v=edges[i].v;
        if(v!=pre){
            dfs1(v,u,d+1);
            size[u]+=size[v];
            if(son[u]==-1||size[son[u]]<size[v])
                son[u]=v;
        }
    }
}
void getpos(int u,int sp){
    top[u]=sp;
    p[u]=pos++;
    fp[p[u]]=u;
    if(son[u]==-1) return ;
    getpos(son[u],sp);
    for(int i=head[u];i!=-1;i=edges[i].next){
        int v=edges[i].v;
        if(v!=son[u]&&v!=fa[u])
            getpos(v,v);
    }
}
int c[maxn];
void add(int x,int v){
    for(int i=x;i<=n;i+=i&-i){
        c[i]+=v;
    }
}
int query(int x){
    int sum=0;
    for(int i=x;i>0;i-=i&-i){
        sum+=c[i];
    }
    return sum;
}
void change(int u,int v,int val){
    int f1=top[u],f2=top[v];
    while(f1!=f2){
        if(deep[f1]<deep[f2]){
            swap(f1,f2);
            swap(u,v);
        }
        add(p[f1],val);
        add(p[u]+1,-val);
        u=fa[f1];f1=top[u];
    }
    if(deep[u]>deep[v]) swap(u,v);
    add(p[u],val);
    add(p[v]+1,-val);
}
int a[maxn];
int main()
{
    int M,P;
    while(scanf("%d%d%d",&n,&M,&P)!=EOF){
        int u,v;
        int C1,C2,K;
        char op[10];
        Init();
        for(int i=1;i<=n;++i) scanf("%d",&a[i]);
        while(M--){
            scanf("%d%d",&u,&v);
            addedge(u,v);
            addedge(v,u);
        }
        dfs1(1,0,0);
        getpos(1,1);
        memset(c,0,sizeof(c));
        for(int i=1;i<=n;++i){
            add(p[i],a[i]);
            add(p[i]+1,-a[i]);
        }
        while(P--){
            scanf("%s",op);
            if(op[0]=='Q'){
                scanf("%d",&u);
                printf("%d\n",query(p[u]));
            }
            else{
                scanf("%d%d%d",&C1,&C2,&K);
                if(op[0]=='D') K=-K;
                change(C1,C2,K);
            }
        }
    }
    return 0;
}