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29 #include <wtf/Assertions.h>
33 // A UnionFind class can be used to compute disjoint sets using the
34 // disjoint-set forest data structure. Each UnionFind instance is a
35 // node in the forest. Typically you use it by using UnionFind as a
38 // class MemberOfSet : public UnionFind<MemberOfSet> { ... }
40 // Calling x->find() gives you a MemberOfSet* that represents the
41 // disjoint set that x belongs to. Calling x->unify(y) unifies x's
42 // set with y's set, and ensures that:
44 // x->find() == y->find()
48 // a->find() == b->find()
50 // for any a, b if prior to the call to x->unify(y), we would have
56 // This implementation is almost amortized O(1), but could be worse
57 // in unlikely pathological cases. It favors having a non-recursive
58 // single pass implementation of unify() and find() over ensuring the
59 // theoretical O(InverseAckermann[n]) amortized bound, which is much
60 // closer to amortized O(1).
72 bool result = !m_parent;
73 ASSERT(result == (const_cast<UnionFind<T>*>(this)->find() == this));
79 T* result = static_cast<T*>(this);
80 T* next = result->m_parent;
83 next = result->m_parent;
93 T* a = static_cast<T*>(this)->find();
110 using WTF::UnionFind;
112 #endif // UnionFind_h