BZOJ1782: [Usaco2010 Feb]slowdown 慢慢游

 1 #include<cstdio>
 2 #include<cstdlib>
 3 #include<cmath>
 4 #include<cstring>
 5 #include<algorithm>
 6 #include<iostream>
 7 #include<vector>
 8 #include<map>
 9 #include<set>
10 #include<queue>
11 #include<string>
12 #define inf 1000000000
13 #define maxn 100000+1000
14 #define maxm 500+100
15 #define eps 1e-10
16 #define ll long long
17 #define pa pair<int,int>
18 using namespace std;
19 inline int read()
20 {
21     int x=0,f=1;char ch=getchar();
22     while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
23     while(ch>=‘0‘&&ch<=‘9‘){x=10*x+ch-‘0‘;ch=getchar();}
24     return x*f;
25 }
26 struct edge{int go,next;}e[2*maxn];
27 int n,tot,ti,s[2*maxn],l[maxn],r[maxn],head[maxn];
28 bool v[maxn];
29 void insert(int x,int y)
30 {
31     e[++tot].go=y;e[tot].next=head[x];head[x]=tot;
32     e[++tot].go=x;e[tot].next=head[y];head[y]=tot;
33 }
34 void dfs(int x)
35 {
36     v[x]=1;
37     l[x]=++ti;
38     for(int i=head[x],y;i;i=e[i].next)
39      if(!v[y=e[i].go])dfs(y);
40     r[x]=++ti; 
41 }
42 void add(int x,int y)
43 {
44     for(;x<=2*n;x+=x&(-x))s[x]+=y;
45 }
46 int sum(int x)
47 {
48     int t=0;
49     for(;x;x-=x&(-x))t+=s[x];
50     return t;
51 }
52 int main()
53 {
54     freopen("input.txt","r",stdin);
55     freopen("output.txt","w",stdout);
56     n=read();
57     int x,y;
58     for(int i=1;i<n;i++)x=read(),y=read(),insert(x,y);
59     dfs(1);
60     for(int i=1;i<=n;i++)
61      {
62          int x=read();
63          printf("%d\n",sum(l[x]));
64          add(l[x],1);add(r[x],-1);
65      } 
66     return 0;
67 }