Alternating Loop

Rules edit

Draw a single continuous loop going through the centers of all cells. The loop cannot touch or cross itself. White and grey circles should alternate going along the loop, i.e. there cannot be two consecutive circles of the same color.

(Rules from WPC 2015 IB, example from PuzzleDuel^[1])

History of the puzzle edit

Invented by Vladimir Portugalov (Belarus) according to a PuzzleDuel Facebook post. Its first appearance is currently unknown. Probably first appeared on forsmarts 12th anniversary contest.^[2]

Appearances in the past WPCs edit

WPC 2015/Round 4 by Vladimir Portugalov

References edit

[1] ttp://www.puzzleduel.club/single/42z5u3u0hkmewdrgn

[2] ttps://logicmastersindia.com/lmitests/dl.asp?attachmentid=481&view=1

[1]

[2]