bzoj 2049: [Sdoi2008]Cave 洞穴勘测

 #include<cstdio>
 #include<iostream>
 using namespace std;
 int  shu[][],n,m,fa[],st[];
 bool rev[];
 bool isroot(int a1)
 {
     return shu[fa[a1]][]!=a1&&shu[fa[a1]][]!=a1;
 }
 void pushdown(int a1)
 {
     int l=shu[a1][],r=shu[a1][];
     if(rev[a1])
       {
         rev[a1]^=;
         rev[l]^=;
         rev[r]^=;
         swap(shu[a1][],shu[a1][]);
       }
 }
 void zhuan(int a1)
 {
     int y=fa[a1],z=fa[y],l,r;
     if(shu[y][]==a1)
       l=;
     else
       l=;
     r=l^;
     if(!isroot(y))
        if(shu[z][]==y)
          shu[z][]=a1;
        else
          shu[z][]=a1;
     fa[a1]=z;
     fa[y]=a1;
     shu[y][l]=shu[a1][r];
     fa[shu[y][l]]=y;
     shu[a1][r]=y;
 }
 void splay(int a1)
 {
     int top=;
     top++;
     st[top]=a1;
     for(int i=a1;!isroot(i);i=fa[i])
       {
         top++;
         st[top]=fa[i];
       }
     for(int i=top;i;i--)
       pushdown(st[i]);
     for(;!isroot(a1);)
       {
         int y=fa[a1],z=fa[a1];
         if(!isroot(y))
           if(y==shu[z][]^a1==shu[y][])
             zhuan(a1);
           else
             zhuan(y);
         zhuan(a1);
       }
 }
 void access(int a1)
 {
     int t=;
     for(;a1;)
       {
         splay(a1);
         shu[a1][]=t;
         t=a1;
         a1=fa[a1];
       }
 }
 void gen(int a1)
 {
     access(a1);
     splay(a1);
     rev[a1]^=;
 }
 void lian(int a1,int a2)
 {
     gen(a1);
     fa[a1]=a2;
     splay(a1);
 }
 void cut(int a1,int a2)
 {
     gen(a1);
     access(a2);
     splay(a2);
     shu[a2][]=fa[a1]=;
 }
 int find(int a1)
 {
     access(a1);
     splay(a1);
     int y;
     for(y=a1;shu[y][];y=shu[y][]);
     return y;
 }
 int main()
 {
     scanf("%d%d",&n,&m);
     for(int i=;i<m;i++)
       {
         int a1,a2;
         char ch[];
         scanf("%s%d%d",ch,&a1,&a2);
         if(ch[]=='C')
           lian(a1,a2);
         if(ch[]=='D')
           cut(a1,a2);
         if(ch[]=='Q')
           {
             int a3,a4;
             a3=find(a1);
             a4=find(a2);
             if(a3==a4)
               printf("Yes\n");
             else
               printf("No\n");
             }
       }
     return ;
 }

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