bzoj 2049 Cave 洞穴勘测(LCT)

  1 #include <iostream>
  2 #include <sstream>
  3 #include <ios>
  4 #include <iomanip>
  5 #include <functional>
  6 #include <algorithm>
  7 #include <vector>
  8 #include <string>
  9 #include <list>
 10 #include <queue>
 11 #include <deque>
 12 #include <stack>
 13 #include <set>
 14 #include <map>
 15 #include <cstdio>
 16 #include <cstdlib>
 17 #include <cmath>
 18 #include <cstring>
 19 #include <climits>
 20 #include <cctype>
 21 using namespace std;
 22 #define XINF INT_MAX
 23 #define INF 0x3FFFFFFF
 24 #define MP(X,Y) make_pair(X,Y)
 25 #define PB(X) push_back(X)
 26 #define REP(X,N) for(int X=0;X<N;X++)
 27 #define REP2(X,L,R) for(int X=L;X<=R;X++)
 28 #define DEP(X,R,L) for(int X=R;X>=L;X--)
 29 #define CLR(A,X) memset(A,X,sizeof(A))
 30 #define IT iterator
 31 typedef long long ll;
 32 typedef pair<int,int> PII;
 33 typedef vector<PII> VII;
 34 typedef vector<int> VI;
 35 #define MAXN 100010
 36 int ch[MAXN][2],key[MAXN],pre[MAXN],size[MAXN],ss[MAXN];
 37 int rev[MAXN];
 38 void push_down(int r){
 39     if(!r)return;
 40     if(rev[r]){
 41         rev[ch[r][0]]^=1;
 42         rev[ch[r][1]]^=1;
 43         swap(ch[r][0],ch[r][1]);
 44         rev[r]=0;
 45     }
 46 }
 47 void rotate(int x,int d){
 48     int y=pre[x];
 49     ch[y][!d]=ch[x][d];
 50     if(ch[x][d])pre[ch[x][d]]=y;
 51     pre[x]=pre[y];
 52     if(ch[pre[y]][0]==y)ch[pre[x]][0]=x;
 53     else if(ch[pre[y]][1]==y)ch[pre[x]][1]=x;
 54     pre[y]=x;
 55     ch[x][d]=y;
 56 }
 57 bool check(int x,int y){
 58     return y&&(ch[y][0]==x||ch[y][1]==x);
 59 }
 60 void splay(int x){
 61     push_down(x);
 62     int y,z;
 63     while(check(x,y=pre[x])){
 64         if(check(y,z=pre[y])){
 65             push_down(z);
 66             push_down(y);
 67             push_down(x);
 68             int d=(y==ch[z][0]);
 69             if(x==ch[y][d]) {rotate(x,!d),rotate(x,d);}
 70             else {rotate(y,d),rotate(x,d);}
 71         }else{
 72             push_down(y);
 73             push_down(x);
 74             rotate(x,ch[y][0]==x);
 75             break;
 76         }
 77     }
 78 }
 79 int access(int u){
 80     int v=0;
 81     for(;u;u=pre[u]){
 82         splay(u);
 83         ch[u][1]=v;
 84         v=u;
 85     }
 86     //splay(u);
 87     return v;
 88 }
 89 int getroot(int x){
 90     for(x=access(x);push_down(x),ch[x][0];x=ch[x][0]);
 91     return x;
 92 }
 93 void makeroot(int x){
 94     rev[access(x)]^=1;
 95     splay(x);
 96 }
 97 void link(int x,int y){
 98     makeroot(x);
 99     pre[x]=y;
100     access(x);
101 }
102 void cut(int x,int y){
103     makeroot(x);
104     access(y);
105     splay(y);
106     pre[ch[y][0]]=0;
107     ch[y][0]=0;
108 }
109 void init(int n){
110     for(int i=0;i<=n;i++)
111         ch[i][0]=ch[i][1]=pre[i]=0;
112 }
113 void query(int x,int y){
114     int ra=getroot(x);
115     int rb=getroot(y);
116     if(ra==rb&&ra)printf("Yes\n");
117     else printf("No\n");
118 }
119 
120 int main()
121 {
122     ios::sync_with_stdio(false);
123     int n,m;
124     while(scanf("%d%d",&n,&m)!=EOF){
125         init(n);
126         int x,y;
127         char a[110];
128         for(int i=0;i<m;i++){
129             scanf("%s%d%d",a,&x,&y);
130             if(a[0]==‘C‘)link(x,y);
131             else if(a[0]==‘D‘)cut(x,y);
132             else query(x,y);
133         }
134     }
135     return 0;
136 }