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Table 1 Summary of results for rearrangement problems

From: Approximation algorithm for rearrangement distances considering repeated genes and intergenic regions

Problem

Rearrangement model

Genome representation

Complexity

Best known approximation factor

Sorting Permutations by Transpositions

Transpositions

Permutation

NP-hard [11]

1.375 [12]

Sorting Permutations by Reversals

Reversals

Permutation

NP-hard [13]

1.375 [14]

Sorting Signed Permutations by Reversals

Reversals

Signed permutation

P [15]

–

Sorting Permutations by Reversals and Transpositions

Reversals and transpositions

Permutation

NP-hard [16]

\(2.8334 + \epsilon\) [17, 18]

Sorting Signed Permutations by Reversals and Transpositions

Reversals and transpositions

Signed permutation

NP-hard [16]

2 [19]

Transposition Distance on Strings

Transpositions

String

NP-hard

\(12k^a\) [20, 21]

Reversal Distance on Strings

Reversals

String

NP-hard

\(16k^a\) [20]

Signed Reversal Distance on Strings

Reversals

Signed string

NP-hard [22]

\(16k^a\) [7, 20]

Sorting Permutations by Intergenic Transpositions

Transpositions

Permutation and sequence of integers

NP-hard [23]

3.5 [23]

Sorting Permutations by Intergenic Reversals

Reversals

Permutation and sequence of integers

NP-hard [24]

4 [24]

Sorting Signed Permutations by Intergenic Reversals

Reversals

Signed permutation and sequence of integers

NP-hard [16]

2 [16]

Sorting Permutations by Intergenic Reversals and Transpositions

Reversals and transpositions

Permutation and sequence of integers

NP-hard [24]

4.5 [24]

Sorting Signed Permutations by Intergenic Reversals and Transpositions

Reversals and transpositions

Signed permutation and sequence of integers

NP-hard [25]

3 [25]

Intergenic Reversal Distance on Strings

Reversals

String and sequence of integers

NP-hard

(Theorem 1)

\(6k^{a,b}\) (Corollary 2)

Intergenic Transposition Distance on Strings

Transposition

String and sequence of integers

NP-hard

(Theorem 1)

\(8k^a\) (Corollary 4)

Intergenic Reversal and Transposition Distance on Strings

Reversal and transposition

String and sequence of integers

NP-hard

(Theorem 1)

\(9k^a\) (Corollary 5)

  1. \({}^a\)Some approximations depend on k, which is the maximum number of copies of a character in the string.
  2. \({}^b\)Asymptotic approximation