Author/Opus: This is the 69th puzzle from our contributing puzzlemaster Prasanna Seshadri.
Rules: Draw a single, non-intersecting loop that passes through all circled cells. All white circles must have equal segment lengths on both sides of the circle before turning. All black circles must have unequal segment lengths on both sides of the circle before turning. Numbers indicate the sum of the segment lengths on both sides of the circle.
Also, see this example:
Answer String: Enter the length in cells of the horizontal loop segments from left to right in the marked rows, starting at the top. If the loop only has vertical segments in the marked row, enter 0. Separate each row’s entry with a comma. This example has the key “11,311”.
Time Standards (highlight to view): Grandmaster = 3:30, Master = 5:45, Expert = 11:30
Note: Follow this link for other less common Loop variations.