Arc reversals in tournaments (Q1102300)

Let \(T_ 1\) and \(T_ 2\) denote two tournaments with the same set of n vertices. If \(2\leq k\leq n\) then the author gives necessary and sufficient conditions for \(T_ 2\) to be obtainable from \(T_ 1\) by a sequence of reversals of the arcs of directed paths with k vertices. And, if \(3\leq k\leq n-2\) and \(T_ 1\) and \(T_ 2\) are strong, he gives necessary and sufficient conditions for \(T_ 2\) to be obtainable from \(T_ 1\) by a sequence of reversals of the arcs of directed cycles with k vertices.