1 #include <cstdio>
 2 #include <iostream>
 3 #define N 10001
 4
 5 int n, m;
 6 int f[N];
 7
 8 inline int read()
 9 {
10     int x = 0, f = 1;
11     char ch = getchar();
12     for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = -1;
13     for(; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + ch - '0';
14     return x * f;
15 }
16
17 inline int find(int x)
18 {
19     while(x ^ f[x]) x = f[x];
20     return x;
21 }
22
23 inline void make_root(int x, int c)
24 {
25     if(x ^ f[x]) make_root(f[x], x);
26     f[x] = c;
27 }
28
29 int main()
30 {
31     int i, j, x, y, fx, fy;
32     char s[10];
33     n = read();
34     m = read();
35     for(i = 1; i <= n; i++) f[i] = i;
36     for(i = 1; i <= m; i++)
37     {
38         scanf("%s", s);
39         x = read();
40         y = read();
41         if(s[0] == 'Q') find(x) == find(y) ? puts("Yes") : puts("No");
42         else if(s[0] == 'C') make_root(x, x), f[x] = y;
43         else make_root(x, x), f[y] = y;
44     }
45     return 0;
46 }

  1 #include <cstdio>
  2 #include <iostream>
  3 #define N 10001
  4 #define swap(x, y) ((x) ^= (y) ^= (x) ^= (y))
  5
  6 int n, m;
  7 int f[N], rev[N], son[N][2], s[N], size[N];
  8
  9 inline int read()
 10 {
 11     int x = 0, f = 1;
 12     char ch = getchar();
 13     for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = -1;
 14     for(; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + ch - '0';
 15     return x * f;
 16 }
 17
 18 inline bool isroot(int x)
 19 {
 20     return son[f[x]][0] ^ x && son[f[x]][1] ^ x;
 21 }
 22
 23 inline int get(int x)
 24 {
 25     return son[f[x]][1] == x;
 26 }
 27
 28 inline void pushdown(int x)
 29 {
 30     if(x && rev[x])
 31     {
 32         swap(son[x][0], son[x][1]);
 33         if(son[x][0]) rev[son[x][0]] ^= 1;
 34         if(son[x][1]) rev[son[x][1]] ^= 1;
 35         rev[x] = 0;
 36     }
 37 }
 38
 39 inline void rotate(int x)
 40 {
 41     int old = f[x], oldf = f[old], wh = get(x);
 42
 43     if(!isroot(old))
 44         son[oldf][son[oldf][1] == old] = x;
 45     f[x] = oldf;
 46
 47     son[old][wh] = son[x][wh ^ 1];
 48     f[son[old][wh]] = old;
 49
 50     son[x][wh ^ 1] = old;
 51     f[old] = x;
 52 }
 53
 54 inline void splay(int x)
 55 {
 56     int i, fa, t = 0;
 57     s[++t] = x;
 58     for(i = x; !isroot(i); i = f[i]) s[++t] = f[i];
 59     for(i = t; i >= 1; i--) pushdown(s[i]);
 60     for(; !isroot(x); rotate(x))
 61         if(!isroot(fa = f[x]))
 62             rotate(get(x) == get(fa) ? fa : x);
 63 }
 64
 65 inline void access(int x)
 66 {
 67     for(int t = 0; x; t = x, x = f[x]) splay(x), son[x][1] = t;
 68 }
 69
 70 inline void reverse(int x)
 71 {
 72     access(x);
 73     splay(x);
 74     rev[x] ^= 1;
 75 }
 76
 77 inline int find(int x)
 78 {
 79     access(x);
 80     splay(x);
 81     while(son[x][0]) x = son[x][0];
 82     return x;
 83 }
 84
 85 inline void link(int x, int y)
 86 {
 87     reverse(x);
 88     f[x] = y;
 89     splay(x);
 90 }
 91
 92 inline void cut(int x, int y)
 93 {
 94     reverse(x);
 95     access(y);
 96     splay(y);
 97     son[y][0] = f[x] = 0;
 98 }
 99
100 int main()
101 {
102     int i, j, x, y;
103     char s[10];
104     n = read();
105     m = read();
106     for(i = 1; i <= m; i++)
107     {
108         scanf("%s", s);
109         x = read();
110         y = read();
111         if(s[0] == 'Q') find(x) == find(y) ? puts("Yes") : puts("No");
112         if(s[0] == 'C') link(x, y);
113         if(s[0] == 'D') cut(x, y);
114     }
115     return 0;
116 }