update：2017.09.26
1 #include <bits/stdc++.h> 2 3 using namespace std; 4 5 struct Link_Cut_Tree 6 { 7 static const int MAXN = 100000 + 7; 8 9 int ch[MAXN][2], fa[MAXN], rev[MAXN], sz[MAXN]; 10 int sk[MAXN]; 11 12 bool isroot(int x) 13 { 14 return ch[fa[x]][0] != x && ch[fa[x]][1] != x; 15 } 16 17 void reverse(int x) 18 { 19 rev[x] ^= 1, swap(ch[x][0],ch[x][1]); 20 } 21 22 void update(int x) 23 { 24 sz[x] = sz[ch[x][0]] + sz[ch[x][1]] +1; 25 } 26 27 void push_down(int x) 28 { 29 if(!rev[x]) return ; 30 if(ch[x][0]) reverse(ch[x][0]); 31 if(ch[x][1]) reverse(ch[x][1]); 32 rev[x]=0; 33 } 34 35 void rotate(int x) 36 { 37 int f = fa[x], gf = fa[f]; 38 int t1 = ( x != ch[f][0]), t2 = ( f != ch[gf][0]), tmp = ch[x][1^t1]; 39 if(!isroot(f)) ch[gf][0^t2] = x; 40 fa[tmp] = f, fa[x] = gf, ch[x][1^t1] = f, fa[f] = x, ch[f][0^t1] = tmp; 41 update(f); 42 } 43 44 void splay(int x) 45 { 46 int top = 0; 47 sk[++top] = x; 48 for(int i = x; !isroot(i); i = fa[i]) sk[++top] = fa[i]; 49 while(top) push_down(sk[top--]); 50 for(int f = fa[x], gf = fa[f]; !isroot(x); rotate(x), f = fa[x],gf = fa[f]) 51 if(!isroot(f)) 52 rotate((x==ch[f][0]) ^ (f==ch[gf][0]) ? x : f); 53 update(x); 54 } 55 56 void access(int x) 57 { 58 for(int p = 0; x; p = x, x = fa[x]) 59 splay(x), ch[x][1] = p, update(x); 60 } 61 62 void makeroot(int x) 63 { 64 access(x), splay(x), reverse(x); 65 } 66 67 int findroot(int x) 68 { 69 access(x), splay(x); 70 while(ch[x][0]) x = ch[x][0]; 71 return x; 72 } 73 void link(int x,int y) 74 { 75 makeroot(x), fa[x] = y; 76 } 77 78 void cut(int x,int y) 79 { 80 makeroot(x), access(y), splay(y); 81 if(ch[y][0] == x) ch[y][0] = fa[x] = 0; 82 update(y); 83 } 84 85 void debug(void) 86 { 87 for(int i=1;i<=100;i++) 88 printf("%d %d %d %d %d %d %d ",i,fa[i],ch[i][0],ch[i][1],rev[i],sz[i]); 89 } 90 }lct; 91 92 int main(void) 93 { 94 95 96 return 0; 97 }