【模板】Splay

如题，这是一个模板。。。

  1 #include <algorithm>
  2 #include <iostream>
  3 #include <cstring>
  4 #include <cstdio>
  5 #include <cctype>
  6 
  7 inline void read(int & x)
  8 {
  9     x = 0;
 10     int k = 1;
 11     char c = getchar();
 12     while (!isdigit(c))
 13         if (c == '-') c = getchar(), k = -1;
 14         else c = getchar();
 15     while (isdigit(c))
 16         x = (x << 1) + (x << 3) + (c ^ 48),
 17         c = getchar();
 18     x *= k;
 19 }
 20 
 21 const int MAXN = 101010;
 22 
 23 int rt = 0, tot = 0;
 24 int faz[MAXN], siz[MAXN], cnt[MAXN], val[MAXN], son[MAXN][2];
 25 
 26 int Getson(int u)
 27 {
 28     return son[faz[u]][1] == u;
 29 }
 30 
 31 void Pushup(int u)
 32 {
 33     siz[u] = siz[son[u][0]] + siz[son[u][1]] + cnt[u];
 34 }
 35 
 36 void Rotate(int u)
 37 {
 38     int y = faz[u], z = faz[y], ch = Getson(u);
 39     int b = son[u][ch ^ 1], d = Getson(y);
 40     son[u][ch ^ 1] = y, son[y][ch] = b;
 41     faz[y] = u, faz[b] = y, faz[u] = z;
 42     if (z) son[z][d] = u;
 43     Pushup(y), Pushup(u);
 44 }
 45 
 46 void Splay(int u, int tar)
 47 {
 48     while (faz[u] != tar)
 49     {
 50         if (faz[faz[u]] != tar)
 51             if (Getson(u) == Getson(faz[u])) Rotate(faz[u]);
 52             else Rotate(u);
 53         Rotate(u);
 54     }
 55     if (!tar) rt = u;
 56 }
 57 
 58 int Getmin(int u)
 59 {
 60     while (son[u][0]) u = son[u][0];
 61     return u;
 62 }
 63 
 64 int Getmax(int u)
 65 {
 66     while (son[u][1]) u = son[u][1];
 67     return u;
 68 }
 69 
 70 int Getx(int x)
 71 {
 72     int cur = rt, las = 0;
 73     while (cur && val[cur] != x)
 74     {
 75         las = cur;
 76         if (x < val[cur]) cur = son[cur][0];
 77         else cur = son[cur][1];
 78     }
 79     return cur ? cur : las;
 80 }
 81 
 82 //void Insert(int x)
 83 //{
 84 //    int u = Getx(x);
 85 //    if (u && val[u] == x)
 86 //    {
 87 //        ++cnt[u];
 88 //        ++siz[u];
 89 //        Splay(u, 0);
 90 //        return;
 91 //    }
 92 //    val[++tot] = x;
 93 //    faz[tot] = u;
 94 //    cnt[tot] = siz[tot] = 1;
 95 //    if (u) son[u][x > val[u]] = tot;
 96 //    if (!rt) rt = tot;
 97 //    Splay(tot, 0);
 98 //}
 99 
100 inline void Insert(int x)
101 {
102     int u = rt, las = 0;
103     while (u)
104     {
105         las = u;
106         if (x == val[u]) 
107         {
108             ++siz[u];
109             ++cnt[u];
110             Splay(u, 0); 
111             return; 
112         }
113         if (x > val[u]) u = son[u][1];
114         else u = son[u][0];
115     }
116     u = ++tot;
117     val[u] = x;
118     faz[u] = las;
119     son[las][x > val[las]] = u;
120     siz[u] = cnt[u] = 1;
121     son[u][0] = son[u][1] = 0;
122     if (!rt) rt = u;
123     Splay(u, 0);
124 }
125 
126 //void Delete(int x)
127 //{
128 //    int u = Getx(x);
129 //    Splay(u, 0);
130 //    if (cnt[u] > 1)  { --cnt[u], --siz[u]; return; }
131 //    if (!son[u][0] || !son[u][1]) { rt = son[u][0] | son[u][1]; faz[rt] = 0; return; }
132 //    faz[son[u][0]] = 0;
133 //    int bg = Getmax(son[u][0]);
134 //    Splay(bg, 0);
135 //    son[bg][1] = son[u][1];
136 //    faz[son[u][1]] = bg;
137 //}
138 
139 inline void Delete(int x)
140 {
141     int u = rt;
142     while (u)
143     {
144         if (x == val[u]) 
145         {
146             Splay(u, 0);
147             if (cnt[u] > 1)
148             { --cnt[u], --siz[u]; return; }
149             if (!son[u][0] || !son[u][1]) 
150             { rt = son[u][0] | son[u][1]; faz[rt] = 0; return; }
151             faz[son[u][0]] = faz[son[u][1]] = 0;
152             int newrt = Getmin(son[u][1]);
153             faz[son[u][0]] = newrt;
154             son[newrt][0] = son[u][0];
155             Splay(newrt, 0);
156             Pushup(newrt);
157             return;
158         }
159         else if (x > val[u]) u = son[u][1];
160         else u = son[u][0];
161     }
162 }
163 
164 inline int GetKth(int k)
165 {
166     int u = rt;
167     while (u)
168         if (siz[son[u][0]] >= k) u = son[u][0];
169         else if (siz[son[u][0]] + cnt[u] < k) k -= siz[son[u][0]] + cnt[u], u = son[u][1];
170         else return val[u];
171 }
172 
173 int GetRank(int x)
174 {
175     int u = Getx(x);
176     Splay(u, 0);
177     return siz[son[u][0]] + 1;
178 }
179 
180 int Pre(int x)
181 {
182     int u = Getx(x);
183        if (val[u] < x) return val[u];
184     return val[Getmax(son[u][0])];
185 }
186 
187 int Suf(int x)
188 {
189     int u = Getx(x);
190        if (val[u] > x) return val[u];
191     return val[Getmin(son[u][1])];
192 }
193 
194 int n, m, opt, x;
195 
196 signed main()
197 {
198     read(m);
199     for (int i = 1; i <= m; ++i)
200     {
201         read(opt), read(x);
202         if (opt == 1) Insert(x);
203         if (opt == 2) Delete(x);
204         if (opt == 3) printf("%d\n", GetRank(x));
205         if (opt == 4) printf("%d\n", GetKth(x));
206         if (opt == 5) printf("%d\n", Pre(x));
207         if (opt == 6) printf("%d\n", Suf(x));
208     }
209     return 0;
210 }