废话不说，有篇论文可供参考：杨思雨：《伸展树的基本操作与应用》
Splay的好处可以快速分裂和合并。
上代码
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//Splay的核心操作splay，在每次插入，删除，查找等操作中都要调用，以用来维护树的平衡，具体证明请网上搜索#include <iostream>using
namespace
std;#define NEW(d) new Splay(d)struct
Splay { Splay* ch[2]; int
key; Splay() : key(0) { ch[0] = ch[1] = NULL; } Splay(int
d) : key(d) { ch[0] = ch[1] = NULL; } int
cmp(int
d) { if(key == d) return
-1; return
key > d ? 0 : 1; }}*root = NULL;typedef
Splay* tree;//左右旋，这里用的技巧是在lrj白书上看到的，旋转不多说，自己理解void
rot(tree& rt, int
d) { tree k = rt-> ch[d^1]; rt-> ch[d^1] = k-> ch[d]; k-> ch[d] = rt; rt = k;}void
splay(tree& rt, int
d) { int
k = rt-> cmp(d); if(k != -1) { tree p = rt-> ch[k]; int
k2 = p-> cmp(d); if(k2 != -1) { splay(p-> ch[k2], d); if(k2 == k) rot(rt, k^1); else
rot(p, k); } rot(rt, k^1); }}tree max(tree rt){ if(rt == NULL) return
NULL; tree ret = rt; while(ret-> ch[1]) ret = ret-> ch[1]; return
ret;}tree min(tree rt){ if(rt == NULL) return
NULL; tree ret = rt; while(ret-> ch[0]) ret = ret-> ch[0]; return
ret;}tree search(tree rt, int
d) { tree ret = rt; while(ret != NULL && ret-> key != d) if(ret-> key > d) ret = ret-> ch[0]; else
ret = ret-> ch[1]; if(ret != NULL) splay(rt, d); else
return
NULL; return
rt;}void
insert(tree& rt, int
d) { if(rt == NULL) { rt = NEW(d); splay(root, d);} else
{ int
p = (rt-> key > d ? 0: 1); insert(rt-> ch[p], d); }}void
del(tree& rt, int
d) { if(search(rt, d) == NULL) return; tree t; if(rt-> ch[0] == NULL) t = rt-> ch[1]; else
{ t = rt-> ch[0]; splay(t, max(t)-> key); t-> ch[1] = rt-> ch[1]; } delete
rt; rt = t;}/*//合并l和r树，前提是r中元素全部大于l的最大元素tree merge(tree l, tree r) { tree m = max(); splay(l, m-> key); l-> ch[1] = r; return l;}//以rt中节点nod分裂rt树为l树和r树，其中nod属于l树void split(tree nod, tree rt, tree& l, tree& r) { splay(rt, nod-> key); l = rt; r = rt-> ch[1]; l-> ch[1] = NULL;}*/void
out(string str) { cout << str;}int
main() { out("1: insert\n2: del\n3: search\n4: max\n5: min\n6: root\n7: Splay\n"); int
c, t; tree a; while(cin >> c) { switch(c) { case
1: cin >> t; insert(root, t); break; case
2: cin >> t; del(root, t); break; case
3: cin >> t; if(search(root, t) == NULL) out("Not here\n"); else
out("Is here!\n"); break; case
4: a = max(root); if(a != NULL) cout << a-> key << endl; else
out("Warn!\n"); break; case
5: a = min(root); if(a != NULL) cout << a-> key << endl; else
out("Warn!\n"); break; case
6: if(root != NULL) { out("root is: "); cout << root-> key << endl; } else
out("Warn!\n"); break; case
7: cin >> t; a = search(root, t); if(a == NULL) out("Not here\n"); else
splay(root, t); break; default: break; } } return
0;} |
原文：http://www.cnblogs.com/iwtwiioi/p/3537061.html