1 #include<cstdio> 2 #include<iostream> 3 using namespace std; 4 int shu[20002][2],n,m,fa[20005],st[20005]; 5 bool rev[20005]; 6 bool isroot(int a1) 7 { 8 return shu[fa[a1]][0]!=a1&&shu[fa[a1]][1]!=a1; 9 } 10 void pushdown(int a1) 11 { 12 int l=shu[a1][0],r=shu[a1][1]; 13 if(rev[a1]) 14 { 15 rev[a1]^=1; 16 rev[l]^=1; 17 rev[r]^=1; 18 swap(shu[a1][0],shu[a1][1]); 19 } 20 } 21 void zhuan(int a1) 22 { 23 int y=fa[a1],z=fa[y],l,r; 24 if(shu[y][0]==a1) 25 l=0; 26 else 27 l=1; 28 r=l^1; 29 if(!isroot(y)) 30 if(shu[z][0]==y) 31 shu[z][0]=a1; 32 else 33 shu[z][1]=a1; 34 fa[a1]=z; 35 fa[y]=a1; 36 shu[y][l]=shu[a1][r]; 37 fa[shu[y][l]]=y; 38 shu[a1][r]=y; 39 } 40 void splay(int a1) 41 { 42 int top=0; 43 top++; 44 st[top]=a1; 45 for(int i=a1;!isroot(i);i=fa[i]) 46 { 47 top++; 48 st[top]=fa[i]; 49 } 50 for(int i=top;i;i--) 51 pushdown(st[i]); 52 for(;!isroot(a1);) 53 { 54 int y=fa[a1],z=fa[a1]; 55 if(!isroot(y)) 56 if(y==shu[z][0]^a1==shu[y][0]) 57 zhuan(a1); 58 else 59 zhuan(y); 60 zhuan(a1); 61 } 62 } 63 void access(int a1) 64 { 65 int t=0; 66 for(;a1;) 67 { 68 splay(a1); 69 shu[a1][1]=t; 70 t=a1; 71 a1=fa[a1]; 72 } 73 } 74 void gen(int a1) 75 { 76 access(a1); 77 splay(a1); 78 rev[a1]^=1; 79 } 80 void lian(int a1,int a2) 81 { 82 gen(a1); 83 fa[a1]=a2; 84 splay(a1); 85 } 86 void cut(int a1,int a2) 87 { 88 gen(a1); 89 access(a2); 90 splay(a2); 91 shu[a2][0]=fa[a1]=0; 92 } 93 int find(int a1) 94 { 95 access(a1); 96 splay(a1); 97 int y; 98 for(y=a1;shu[y][0];y=shu[y][0]); 99 return y; 100 } 101 int main() 102 { 103 scanf("%d%d",&n,&m); 104 for(int i=0;i<m;i++) 105 { 106 int a1,a2; 107 char ch[10]; 108 scanf("%s%d%d",ch,&a1,&a2); 109 if(ch[0]=='C') 110 lian(a1,a2); 111 if(ch[0]=='D') 112 cut(a1,a2); 113 if(ch[0]=='Q') 114 { 115 int a3,a4; 116 a3=find(a1); 117 a4=find(a2); 118 if(a3==a4) 119 printf("Yes\n"); 120 else 121 printf("No\n"); 122 } 123 } 124 return 0; 125 }
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