Abstract
The
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$${ \mathcal{R}^{ + - }}{ \mathcal{F}^{ + - }}$$
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Consistency problem takes as input two sets
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$${R^ + }$$
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and
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$${R^ - }$$
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of resolved triplets and two sets
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$${F^ + }$$
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and
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$${F^ - }$$
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of fan triplets, and asks for a distinctly leaf-labeled tree that contains all elements in
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$${R^ + } \cup {F^ + }$$
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and no elements in
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$${R^ - } \cup {F^ - }$$
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as embedded subtrees, if such a tree exists. This article presents a detailed characterization of how the computational complexity of the problem changes under various restrictions. Our main result is an efficient algorithm for dense inputs satisfying
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$${R^ - } = \emptyset$$
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whose running time is linear in the size of the input and therefore optimal.