We resolve positively a long standing open question regarding the fixed-parameter tractability of the parameterized Directed Feedback Vertex Set problem. In particular, we propose an algorithm which solves this problem in O(8kk!∗poly(n)).
Cite
@article{arxiv.0707.0282,
title = {Directed Feedback Vertex Set is Fixed-Parameter Tractable},
author = {Igor Razgon and Barry O'Sullivan},
journal= {arXiv preprint arXiv:0707.0282},
year = {2007}
}