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Test cases test001-in.nq to test062-in.nq are from [1] licensed under the W3C BSD 3-clause license. Test cases hogan*.nq are from the original paper used with permission. [1]https://json-ld.github.io/normalization/tests/index.html
57 lines
1.1 KiB
Go
57 lines
1.1 KiB
Go
// Copyright ©2020 The Gonum Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package rdf
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// djSet implements a disjoint set finder using the union-find algorithm.
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type djSet map[string]*dsNode
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// add adds e to the collection of sets held by the disjoint set.
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func (s djSet) add(e string) {
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if _, ok := s[e]; ok {
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return
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}
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s[e] = &dsNode{}
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}
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// union joins two sets a and b within the collection of sets held by
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// the disjoint set.
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func (djSet) union(a, b *dsNode) {
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ra := find(a)
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rb := find(b)
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if ra == rb {
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return
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}
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if ra.rank < rb.rank {
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ra.parent = rb
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return
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}
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rb.parent = ra
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if ra.rank == rb.rank {
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ra.rank++
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}
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}
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// find returns the root of the set containing e.
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func (s djSet) find(e string) *dsNode {
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n, ok := s[e]
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if !ok {
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return nil
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}
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return find(n)
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}
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// find returns the root of the set containing the set node, n.
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func find(n *dsNode) *dsNode {
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for ; n.parent != nil; n = n.parent {
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}
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return n
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}
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// dsNode is a disjoint set element.
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type dsNode struct {
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parent *dsNode
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rank int
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}
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