[BZOJ3674]可持久化并查集加强版&[BZOJ3673]可持久化并查集 by zky

思路：

用主席树维护并查集森林，每次连接时新增结点。
似乎并不需要启发式合并，我随随便便写了一个就跑到了3674第一页？
3673是这题的弱化版，本来写个暴力就能过，现在借用加强版的代码（去掉异或），直接吊打暴力程序。

 #include<cstdio>
 #include<cctype>
 inline int getint() {
     register char ch;
     while(!isdigit(ch=getchar()));
     register int x=ch^'';
     while(isdigit(ch=getchar())) x=(((x<<)+x)<<)+(ch^'');
     return x;
 }
 const int N=,SIZE=;
 class PresistentDisjointSet {
     private:
         unsigned int left[SIZE],right[SIZE],sz;
         int anc[SIZE];
         unsigned int newnode() {
             return sz++;
         }
         unsigned int getpos(const unsigned int p,const int b,const int e,const int x) {
             if(b==e) return p;
             int mid=(b+e)>>;
             return (x<=mid)?getpos(left[p],b,mid,x):getpos(right[p],mid+,e,x);
         }
     public:
         unsigned int root[N];
         PresistentDisjointSet() {
             sz=;
         }
         void Build(unsigned int &p,const int b,const int e) {
             p=newnode();
             if(b==e) {
                 anc[p]=b;
                 return;
             }
             int mid=(b+e)>>;
             Build(left[p],b,mid);
             Build(right[p],mid+,e);
         }
         unsigned int find(const unsigned int p,const int b,const int e,const int x) {
             int q=getpos(p,b,e,x);
             return x==anc[q]?q:find(p,b,e,anc[q]);
         }
         unsigned int Union2(const unsigned int p,const int b,const int e,const int x,const int y) {
             unsigned int new_p=newnode();
             if(b==e) {
                 anc[new_p]=y;
                 return new_p;
             }
             int mid=(b+e)>>;
             if(x<=mid) left[new_p]=Union2(left[p],b,mid,x,y),right[new_p]=right[p];
             if(x>mid) right[new_p]=Union2(right[p],mid+,e,x,y),left[new_p]=left[p];
             return new_p;
         }
         bool isConnected(const int x,const int y) {
             return anc[x]==anc[y];
         }
         unsigned int Union(const unsigned int p,const int b,const int e,int x,int y) {
             x=find(p,b,e,x),y=find(p,b,e,y);
             if(isConnected(x,y)) return p;
             return Union2(p,b,e,anc[x],anc[y]);
         }
 };
 PresistentDisjointSet s;
 int main() {
     int n=getint(),lastans=;
     s.Build(s.root[],,n);
     int m=getint();
     for(register int i=;i<=m;i++) {
         int op=getint();
         if(op==) s.root[i]=s.Union(s.root[i-],,n,getint()^lastans,getint()^lastans);
         else if(op==) s.root[i]=s.root[getint()^lastans];
         else s.root[i]=s.root[i-],printf("%d\n",lastans=s.isConnected(s.find(s.root[i],,n,getint()^lastans),s.find(s.root[i],,n,getint()^lastans)));
     }
     return ;
 }