BZOJ 4034: [HAOI 2015] 트 리 조작 (낙 곡 P3178)

#include
#include
#include
#include
#define N 100005
using namespace std;
typedef long long LL;
struct tree{ int l,r; LL sum,tg; }t[N*4];
struct edge{ int next,to; }ed[N*2];
int n,m,nd,k,a[N],fa[N],dep[N],to[N],h[N],tp[N],sz[N],L[N],R[N],in[N];
inline char readc(){
    static char buf[100000],*l=buf,*r=buf;
    if (l==r) r=(l=buf)+fread(buf,1,100000,stdin);
    if (l==r) return EOF; return *l++;
}
inline int _read(){
    int num=0,f=1; char ch=readc();
    while (!isdigit(ch)) { if (ch=='-') f=-1; ch=readc(); }
    while (isdigit(ch)) num=(num<<3)+(num<<1)+(ch^48),ch=readc();
    return num*f;
}
inline void addedge(int x,int y){
    ed[++k].next=h[x],ed[k].to=y,h[x]=k;
}
void dfs1(int x,int depth){
    sz[x]=1,dep[x]=depth;
    for (int i=h[x];i;i=ed[i].next)
        if (ed[i].to!=fa[x]){
            int v=ed[i].to; 
            fa[v]=x,dfs1(v,depth+1),sz[x]+=sz[v];
            if (sz[v]>sz[to[x]]) to[x]=v;
        }
}
void dfs2(int x){
    L[x]=++nd,in[nd]=x;
    for (int i=h[x];i;i=ed[i].next)
        if (ed[i].to==to[x])
            tp[ed[i].to]=tp[x],dfs2(ed[i].to);
    for (int i=h[x];i;i=ed[i].next)
        if (ed[i].to!=to[x]&&ed[i].to!=fa[x])
            tp[ed[i].to]=ed[i].to,dfs2(ed[i].to);
    R[x]=nd;
}
void build(int l,int r,int x){
    t[x].l=l,t[x].r=r;
    if (l==r){ t[x].sum=a[in[l]]; return; }
    int mid=l+r>>1; build(l,mid,x*2),build(mid+1,r,x*2+1);
    t[x].sum=t[x*2].sum+t[x*2+1].sum;
}
inline void pshd(int x){
    t[x*2].tg+=t[x].tg,t[x*2+1].tg+=t[x].tg;
    t[x*2].sum+=t[x].tg*(t[x*2].r-t[x*2].l+1);
    t[x*2+1].sum+=t[x].tg*(t[x*2+1].r-t[x*2+1].l+1);
    t[x].tg=0;
}
void mdfy(int x,int l,int r,int w){
    if (t[x].l>r||t[x].rreturn;
    if (t[x].l>=l&&t[x].r<=r){
        t[x].sum+=(t[x].r-t[x].l+1)*(LL)w;//      LL
        t[x].tg+=w; return; 
    }
    if (t[x].tg) pshd(x);
    mdfy(x*2,l,r,w),mdfy(x*2+1,l,r,w);
    t[x].sum=t[x*2].sum+t[x*2+1].sum;
}
LL find(int x,int l,int r){
    if (t[x].l>r||t[x].rreturn 0;
    if (t[x].l>=l&&t[x].r<=r) return t[x].sum;
    if (t[x].tg) pshd(x);
    return find(x*2,l,r)+find(x*2+1,l,r);
}
inline LL srch(int x,int y){
    LL ans=0;
    while (tp[x]!=tp[y]){
        if (dep[tp[x]]1,L[tp[x]],L[x]),x=fa[tp[x]];
    }
    if (dep[x]return ans+=find(1,L[y],L[x]);
}
int main(){
    n=_read(),m=_read();
    for (int i=1;i<=n;i++) a[i]=_read();
    for (int i=1;iint u=_read(),v=_read();
        addedge(u,v),addedge(v,u);
    }
    dfs1(1,1),tp[1]=1,dfs2(1),build(1,n,1);
    while (m--){
        int flag=_read(),x=_read(),z;
        switch (flag){
            case 1: z=_read(),mdfy(1,L[x],L[x],z); break;
            case 2: z=_read(),mdfy(1,L[x],R[x],z); break;
            case 3: printf("%lld
",srch(1,x)); break;
        }
    }
    return 0;
}