bzoj 2049 Cave 洞穴勘测(LCT)

转载请注明出处： http://www.cnblogs.com/fraud/          ——by fraud

动态树入门题，不需要维护任何信息。

我用的是splay，下标实现的lct。

 #include <iostream>
 #include <sstream>
 #include <ios>
 #include <iomanip>
 #include <functional>
 #include <algorithm>
 #include <vector>
 #include <string>
 #include <list>
 #include <queue>
 #include <deque>
 #include <stack>
 #include <set>
 #include <map>
 #include <cstdio>
 #include <cstdlib>
 #include <cmath>
 #include <cstring>
 #include <climits>
 #include <cctype>
 using namespace std;
 #define XINF INT_MAX
 #define INF 0x3FFFFFFF
 #define MP(X,Y) make_pair(X,Y)
 #define PB(X) push_back(X)
 #define REP(X,N) for(int X=0;X<N;X++)
 #define REP2(X,L,R) for(int X=L;X<=R;X++)
 #define DEP(X,R,L) for(int X=R;X>=L;X--)
 #define CLR(A,X) memset(A,X,sizeof(A))
 #define IT iterator
 typedef long long ll;
 typedef pair<int,int> PII;
 typedef vector<PII> VII;
 typedef vector<int> VI;
 #define MAXN 100010
 int ch[MAXN][],key[MAXN],pre[MAXN],size[MAXN],ss[MAXN];
 int rev[MAXN];
 void push_down(int r){
     if(!r)return;
     if(rev[r]){
         rev[ch[r][]]^=;
         rev[ch[r][]]^=;
         swap(ch[r][],ch[r][]);
         rev[r]=;
     }
 }
 void rotate(int x,int d){
     int y=pre[x];
     ch[y][!d]=ch[x][d];
     if(ch[x][d])pre[ch[x][d]]=y;
     pre[x]=pre[y];
     if(ch[pre[y]][]==y)ch[pre[x]][]=x;
     else if(ch[pre[y]][]==y)ch[pre[x]][]=x;
     pre[y]=x;
     ch[x][d]=y;
 }
 bool check(int x,int y){
     return y&&(ch[y][]==x||ch[y][]==x);
 }
 void splay(int x){
     push_down(x);
     int y,z;
     while(check(x,y=pre[x])){
         if(check(y,z=pre[y])){
             push_down(z);
             push_down(y);
             push_down(x);
             int d=(y==ch[z][]);
             if(x==ch[y][d]) {rotate(x,!d),rotate(x,d);}
             else {rotate(y,d),rotate(x,d);}
         }else{
             push_down(y);
             push_down(x);
             rotate(x,ch[y][]==x);
             break;
         }
     }
 }
 int access(int u){
     int v=;
     for(;u;u=pre[u]){
         splay(u);
         ch[u][]=v;
         v=u;
     }
     //splay(u);
     return v;
 }
 int getroot(int x){
     for(x=access(x);push_down(x),ch[x][];x=ch[x][]);
     return x;
 }
 void makeroot(int x){
     rev[access(x)]^=;
     splay(x);
 }
 void link(int x,int y){
     makeroot(x);
     pre[x]=y;
     access(x);
 }
 void cut(int x,int y){
     makeroot(x);
     access(y);
     splay(y);
     pre[ch[y][]]=;
     ch[y][]=;
 }
 void init(int n){
     for(int i=;i<=n;i++)
         ch[i][]=ch[i][]=pre[i]=;
 }
 void query(int x,int y){
     int ra=getroot(x);
     int rb=getroot(y);
     if(ra==rb&&ra)printf("Yes\n");
     else printf("No\n");
 }

 int main()
 {
     ios::sync_with_stdio(false);
     int n,m;
     while(scanf("%d%d",&n,&m)!=EOF){
         init(n);
         int x,y;
         char a[];
         for(int i=;i<m;i++){
             scanf("%s%d%d",a,&x,&y);
             if(a[]=='C')link(x,y);
             else if(a[]=='D')cut(x,y);
             else query(x,y);
         }
     }
     return ;
 }