BZOJ-4034: [HAOI2015]树上操作 (线段树+DFS序)

 1 #include "bits/stdc++.h"
 2 #define lson rt<<1,l,m
 3 #define rson rt<<1|1,m+1,r
 4 using namespace std;
 5 typedef long long LL;
 6 const int MAX=1e5+5;
 7 LL n,m,a[MAX];
 8 LL tot,head[MAX],adj[MAX],next[MAX];
 9 LL tx,cc[MAX],vv[MAX],fa[MAX];
10 LL c[MAX<<2],la[MAX<<2];
11 bool vis[MAX];
12 inline LL read(){
13     LL an=0,x=1;char c=getchar();
14     while (c<‘0‘ || c>‘9‘) {if (c==‘-‘) x=-1;c=getchar();}
15     while (c>=‘0‘ && c<=‘9‘) {an=an*10+c-‘0‘;c=getchar();}
16     return an*x;
17 }
18 void addedge(int u,int v){tot++; adj[tot]=v; next[tot]=head[u]; head[u]=tot;}
19 void PushUp(int rt){
20     c[rt]=c[rt<<1]+c[rt<<1|1];
21 }
22 void PushDown(int rt,int l,int r){
23     int m=(l+r)>>1;
24     if (la[rt]){
25         la[rt<<1]+=la[rt],la[rt<<1|1]+=la[rt];
26         c[rt<<1]+=la[rt]*(m-l+1);
27         c[rt<<1|1]+=la[rt]*(r-m);
28         la[rt]=0;
29     }
30 }
31 void update(int rt,int l,int r,int x,int y,LL z){
32     if (x<=l && r<=y){
33         la[rt]+=z; c[rt]+=(r-l+1)*z;
34         return;
35     }
36     int m=(l+r)>>1;
37     PushDown(rt,l,r);
38     if (x<=m) update(lson,x,y,z);
39     if (y>m) update(rson,x,y,z);
40     PushUp(rt);
41 }
42 LL query(int rt,int l,int r,LL x){
43     if (l==r && l==x)
44         return c[rt];
45     int m=(l+r)>>1;LL cnt=0;
46     PushDown(rt,l,r);
47     if (x<=m) cnt+=query(lson,x);
48     else cnt+=query(rson,x);
49     return cnt;
50 }
51 void dfs(int x){
52     cc[x]=++tx;vis[x]=true;
53     int i,j;
54     for (i=head[x];i;i=next[i])
55         if (!vis[adj[i]])
56             fa[adj[i]]=x,dfs(adj[i]);
57     vv[x]=tx;
58 }
59 LL calc(int x){
60     if (x==1) return query(1,1,n,cc[x]);
61     return query(1,1,n,cc[x])+calc(fa[x]);
62 }
63 int main(){
64     freopen ("tree.in","r",stdin);
65     freopen ("tree.out","w",stdout);
66     int i,j,x,y,z,u,v;
67     n=read(),m=read();
68     for (i=1;i<=n;i++) a[i]=read();
69     for (i=1;i<n;i++){
70         u=read(),v=read();
71         addedge(u,v),addedge(v,u);
72     }
73     fa[1]=0,dfs(1);
74     for (i=1;i<=n;i++) update(1,1,n,cc[i],cc[i],a[i]);
75     for (i=1;i<=m;i++){
76         z=read();
77         if (z==1) x=read(),y=read(),update(1,1,n,cc[x],cc[x],y);
78         if (z==2) x=read(),y=read(),update(1,1,n,cc[x],vv[x],y);
79         if (z==3) x=read(),printf("%lld\n",calc(x));
80     }
81     return 0;
82 }