Luogu 2147 洞穴勘测 - LCT

Solution

$LCT$ 打上 $cut$ ， $link$ 和 $finroot$ 即可

Code

 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #define rd read()
 using namespace std;

 const int N = 1e4 + ;

 int n, m;

 int read() {
     int X = , p = ; char c = getchar();
     for (; c > '' || c < ''; c = getchar())
         if (c == '-') p = -;
     for (; c >= '' && c <= ''; c = getchar())
         X = X *  + c - '';
     return X * p;
 }

 namespace LCT {
     int f[N], ch[N][], tun[N];
 #define lc(x) ch[x][0]
 #define rc(x) ch[x][1]

     int isroot(int x) {
         return rc(f[x]) != x && lc(f[x]) != x;
     }

     int get(int x) {
         return rc(f[x]) == x;
     }

     void rev(int x) {
         swap(lc(x), rc(x));
         tun[x] ^= ;
     }

     void pushdown(int x) {
         if (tun[x]) {
             if (lc(x)) rev(lc(x));
             if (rc(x)) rev(rc(x));
             tun[x] = ;
         }
     }

     void pd(int x) {
         if (!isroot(x))
             pd(f[x]);
         pushdown(x);
     }

     void rotate(int x) {
         int old = f[x], oldf = f[old], son = ch[x][get(x) ^ ];
         if (!isroot(old)) ch[oldf][get(old)] = x;
         ch[x][get(x) ^ ] = old;
         ch[old][get(x)] = son;
         f[old] = x; f[x] = oldf; f[son] = old;
     }

     void splay(int x) {
         pd(x);
         for (; !isroot(x); rotate(x))
             if (!isroot(f[x]))
                 rotate(get(f[x]) == get(x) ? f[x] : x);
     }

     void access(int x) {
         for (int y = ; x; y = x, x = f[x])
             splay(x), ch[x][] = y;
     }

     void mroot(int x) {
         access(x); splay(x); rev(x);
     }

     int findr(int x) {
         access(x); splay(x);
         while(lc(x)) pushdown(x), x = lc(x);
         return x;
     }

     void split(int x, int y) {
         mroot(x); access(y); splay(y);
     }

     void cut(int x, int y) {
         split(x, y);
         f[x] = ch[y][] = ;
     }

     void link(int x, int y) {
         mroot(x);
         f[x] = y;
     }
 }using namespace LCT;

 int main()
 {
     n = rd; m = rd;
     for (; m; m--) {
         char op[];
         scanf("%s", op);
         if (op[] == 'Q') {
             int u = rd, v = rd;
             mroot(u);
             if (findr(v) != u)
                 puts("No");
             else puts("Yes");
         }
         if (op[] == 'C') {
             int u = rd,  v = rd;
             link(u, v);
         }
         if (op[] == 'D') {
             int u = rd, v = rd;
             cut(u, v);
         }
     }
 }