“…, N. A track can be referred to either by its number, i, or by its endpoints, [2i − 1, 2i]. For a field with 8 tracks, a solution could be noted as a sequence of all 16 track endpoints, e.g., [0,8,7,11,12,6,5,1,2,4,3,9,10,16,15,13,14,0], where 0 is a common starting and ending point of the route. In this solution, the first track to visit is number 4 in the direction from endpoint 8 to 7, then track 6 in the direction from endpoint 11 to 12, and so forth.…”