【模板】有旋Treap

如题，这是一个模板。。。

 #include <algorithm>
 #include <iostream>
 #include <cstring>
 #include <cstdio>
 #include <cctype>

 inline void read(int & x)
 {
     x = ;
     int k = ;
     char c = getchar();
     while (!isdigit(c))
         if (c == '-') c = getchar(), k = -;
         else c = getchar();
     while (isdigit(c))
         x = (x << ) + (x << ) + (c ^ ),
         c = getchar();
     x *= k;
 }

 const int MAXN = ;
 int n, tot = , rt = ;
 int cnt[MAXN], siz[MAXN], val[MAXN], rnd[MAXN];
 int son[MAXN][];

 inline int Rand(void)
 {
     static int seed = ;
     return seed = (int)seed * 482711LL % ;
 }

 inline void Pushup(int u)
 {
     siz[u] = siz[son[u][]] + siz[son[u][]] + cnt[u];
 }

 inline void Rotate(int &u, int ch)
 {
     int b = son[u][ch ^ ];
     son[u][ch ^ ] = son[b][ch];
     son[b][ch] = u;
     Pushup(u), Pushup(u = b);
 }

 inline void Insert(int &u, int x)
 {
     if (!u)
     {
         u = ++tot;
         cnt[u] = siz[u] = ;
         val[u] = x, rnd[u] = Rand();
         son[u][] = son[u][] = ;
         return;
     }
     ++siz[u];
     if (val[u] == x) { ++cnt[u]; return; }
     int ch = val[u] < x; Insert(son[u][ch], x);
     if (rnd[u] > rnd[son[u][ch]]) Rotate(u, ch ^ );
 }

 inline void Delete(int &u, int x)
 {
     if (!u) return;
     if (val[u] == x)
     {
         if (cnt[u] > ) { --cnt[u], --siz[u]; return; }
         int ch = rnd[son[u][]] < rnd[son[u][]];
         if (!son[u][] || !son[u][]) u = son[u][] + son[u][];
         else Rotate(u, ch), Delete(u, x);
     }
     else --siz[u], Delete(son[u][val[u] < x], x);
 }

 inline int Getrank(int u, int x)
 {
     if (!u) return ;
     if (val[u] == x) return siz[son[u][]] + ;
     if (val[u] > x) return Getrank(son[u][], x);
     else return Getrank(son[u][], x) + siz[son[u][]] + cnt[u];
 }

 inline int Getkth(int k)
 {
     int u = rt;
     while (true)
         if (k <= siz[son[u][]]) u = son[u][];
         else if (k > siz[son[u][]] + cnt[u])
             k -= siz[son[u][]] + cnt[u], u = son[u][];
         else return val[u];
 }

 inline int Pre(int x)
 {
     int u = rt, pre = -;
     while (u)
         if (x > val[u]) pre = val[u], u = son[u][];
         else u = son[u][];
     return pre;
 }

 inline int Suf(int x)
 {
     int u = rt, suf = ;
     while (u)
         if (x < val[u]) suf = val[u], u = son[u][];
         else u = son[u][];
     return suf;
 }

 int opt, x;

 signed main()
 {
     read(n);
     for (int i = ; i <= n; ++i)
     {
         read(opt), read(x);
         if (opt == ) Insert(rt, x);
         if (opt == ) Delete(rt, x);
         if (opt == ) printf("%d\n", Getrank(rt, x));
         if (opt == ) printf("%d\n", Getkth(x));
         if (opt == ) printf("%d\n", Pre(x));
         if (opt == ) printf("%d\n", Suf(x));
     }
     return ;
 }