Unshuffling a Square is NP-Hard
Computational Complexity
2012-12-03 v1
Abstract
A shuffle of two strings is formed by interleaving the characters into a new string, keeping the characters of each string in order. A string is a square if it is a shuffle of two identical strings. There is a known polynomial time dynamic programming algorithm to determine if a given string z is the shuffle of two given strings x,y; however, it has been an open question whether there is a polynomial time algorithm to determine if a given string z is a square. We resolve this by proving that this problem is NP-complete via a many-one reduction from 3- Partition.
Keywords
Cite
@article{arxiv.1211.7161,
title = {Unshuffling a Square is NP-Hard},
author = {Sam Buss and Michael Soltys},
journal= {arXiv preprint arXiv:1211.7161},
year = {2012}
}