hdu3966 Aragorn's Story（树链剖分）

点权裸题

#include 
#include 
#include 
using namespace std;
#define ll long long
#define inf 0x3f3f3f3f
#define N 50010
inline int read(){
    int x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-') f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar();
    return x*f;
}
int n,m,q,a[N],w[N],h[N],num=0,fa[N],dep[N],son[N],size[N],top[N],id[N],dfn=0;
struct edge{
    int to,next;
}data[N<<1];
struct node{
    int add,x;
}tree[N<<2];
void dfs1(int x){
    size[x]=1;
    for(int i=h[x];i;i=data[i].next){
        int y=data[i].to;
        if(fa[x]==y) continue;
        fa[y]=x;dep[y]=dep[x]+1;dfs1(y);size[x]+=size[y];
        if(size[y]>size[son[x]]) son[x]=y;
    }
}
void dfs2(int x,int tp){
    id[x]=++dfn;top[x]=tp;w[dfn]=a[x];
    if(son[x]) dfs2(son[x],tp);
    for(int i=h[x];i;i=data[i].next){
        int y=data[i].to;
        if(y==fa[x]||y==son[x]) continue;
        dfs2(y,y);
    }
}
void build(int p,int l,int r){
    tree[p].add=0;
    if(l==r){tree[p].x=w[l];return;}
    int mid=l+r>>1;
    build(p<<1,l,mid);build(p<<1|1,mid+1,r);
}
void pushdown(int p){
    if(!tree[p].add) return;
    tree[p<<1].add+=tree[p].add;tree[p<<1|1].add+=tree[p].add;
    tree[p<<1].x+=tree[p].add;tree[p<<1|1].x+=tree[p].add;
    tree[p].add=0;
}
void add1(int p,int l,int r,int x,int y,int val){
    if(x<=l&&r<=y){tree[p].add+=val;tree[p].x+=val;return;}
    int mid=l+r>>1;pushdown(p);
    if(x<=mid) add1(p<<1,l,mid,x,y,val);
    if(y>mid) add1(p<<1|1,mid+1,r,x,y,val);
}
int query(int p,int l,int r,int x){
    if(l==r) return tree[p].x;
    int mid=l+r>>1;pushdown(p);
    if(x<=mid) return query(p<<1,l,mid,x);
    else return query(p<<1|1,mid+1,r,x);
}
void doadd(int x,int y,int val){
    while(top[x]!=top[y]){
        if(dep[top[x]]1,1,n,id[top[x]],id[x],val);
        x=fa[top[x]];
    }
    if(id[x]>id[y]) swap(x,y);
    add1(1,1,n,id[x],id[y],val);
}
int main(){
//  freopen("a.in","r",stdin);
    while(~scanf("%d%d%d",&n,&m,&q)){
        memset(h,0,sizeof(h));memset(fa,0,sizeof(fa));
        memset(son,0,sizeof(son));num=dfn=0;
        for(int i=1;i<=n;++i) a[i]=read();
        for(int i=1;iint x=read(),y=read();
            data[++num].to=y;data[num].next=h[x];h[x]=num;
            data[++num].to=x;data[num].next=h[y];h[y]=num;
        }
        dep[1]=1;dfs1(1);dfs2(1,1);build(1,1,n);
        while(q--){
            char op[1];scanf("%s",op);int x=read();
            if(op[0]=='I'){int y=read(),val=read();doadd(x,y,val);}
            if(op[0]=='D'){int y=read(),val=read();doadd(x,y,-val);}
            if(op[0]=='Q') printf("%d\n",query(1,1,n,id[x]));
        }
    }
    return 0;
}