Approximating reversal distance for strings with bounded number of duplicates Original Research Article

For a string image, a reversal image, image, transforms the string A into a string image image, that is, the reversal image reverses the order of symbols in the substring image of A. In the case of signed strings, where each symbol is given a sign image or image, the reversal operation also flips the sign of each symbol in the reversed substring. Given two strings, A and B, signed or unsigned, sorting by reversals (SBR) is the problem of finding the minimum number of reversals that transform the string A into the string B.