bzoj 2049 Cave 洞穴勘测(LCT)

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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。

 

  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 }