BZOJ1036: [ZJOI2008]树的统计Count

  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 30000+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,m,tot,head[maxn],fa[maxn],c[maxn][2],sta[maxn],next[maxn],mx[maxn],sum[maxn],v[maxn];
 28 bool rev[maxn];
 29 inline 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 inline bool isroot(int x)
 35 {
 36     return c[fa[x]][0]!=x&&c[fa[x]][1]!=x;
 37 }
 38 inline void pushup(int x)
 39 {
 40     mx[x]=max(v[x],max(mx[c[x][0]],mx[c[x][1]]));
 41     sum[x]=sum[c[x][0]]+sum[c[x][1]]+v[x];
 42 }
 43 void rotate(int x)
 44 {
 45     int y=fa[x],z=fa[y],l=(c[y][1]==x),r=l^1;
 46     if(!isroot(y))c[z][c[z][1]==y]=x;
 47     fa[x]=z;fa[y]=x;fa[c[x][r]]=y;
 48     c[y][l]=c[x][r];c[x][r]=y;
 49     pushup(y);pushup(x);
 50 }
 51 void pushdown(int x)
 52 {
 53     if(!rev[x])return;
 54     rev[x]^=1;rev[c[x][0]]^=1;rev[c[x][1]]^=1;
 55     swap(c[x][0],c[x][1]);
 56 }
 57 void splay(int x)
 58 {
 59     int top=0;sta[++top]=x;
 60     for(int y=x;!isroot(y);y=fa[y])sta[++top]=fa[y];
 61     for(;top;)pushdown(sta[top--]);
 62     while(!isroot(x))
 63     {
 64         int y=fa[x],z=fa[y];
 65         if(!isroot(y))
 66          {
 67              if(c[z][0]==y^c[y][0]==x)rotate(x);else rotate(y);
 68          }
 69         rotate(x); 
 70     }
 71     
 72 }
 73 void access(int x)
 74 {
 75     for(int y=0;x;x=fa[x])
 76     {
 77         splay(x);c[x][1]=y;pushup(x);y=x;
 78     }
 79 }
 80 void makeroot(int x)
 81 {
 82     access(x);splay(x);rev[x]^=1;
 83 }
 84 int find(int x)
 85 {
 86     access(x);splay(x);
 87     while(c[x][0])x=c[x][0];
 88     return x;
 89 }
 90 void link(int x,int y)
 91 {
 92     makeroot(x);fa[x]=y;splay(x);
 93 }
 94 void cut(int x,int y)
 95 {
 96     makeroot(x);access(y);splay(y);c[y][0]=fa[x]=0;
 97 }
 98 int main()
 99 {
100     freopen("input.txt","r",stdin);
101     freopen("output.txt","w",stdout);
102     n=read();
103     int x,y,top=0;char ch[10];
104     for(int i=1;i<n;i++)x=read(),y=read(),insert(x,y);
105     for(int i=1;i<=n;i++)mx[i]=sum[i]=v[i]=read();
106     sta[++top]=1;
107     for(int i=1;i<=top;i++)
108      for(int k=sta[i],j=head[k];j;j=e[j].next)
109       if(e[j].go!=fa[k])
110        {
111            fa[y=e[j].go]=k;sta[++top]=y;
112        }  
113     mx[0]=-inf;
114     m=read();
115     while(m--)
116     {
117         scanf("%s",ch);x=read();y=read();
118         if(ch[0]==‘C‘)
119         {
120             makeroot(x);v[x]=y;pushup(x);
121         }
122         else
123         {
124             makeroot(x);
125             access(y);splay(y);printf("%d\n",ch[1]==‘M‘?mx[y]:sum[y]);
126         }
127     }   
128     return 0;
129 }