# A bicolour masyu

This is a bicolour masyu puzzle. Instead of making one continuous loop, the goal is to make two separate loops, one blue and one red. The coloured circles must be used for the loop of the same colour, whereas black circles can be used for either colour.

• will the two loops intersect? Jul 21 '19 at 13:23
• Covering all cells is not required in masyu. The two loops can't cross each other.
– Jafe
Jul 21 '19 at 13:25
• I'm glad you made that clear, I misread the linked rules Jul 21 '19 at 13:32

## 1 Answer

I believe this is the unique solution:

Key steps:

Solid circle near bottom right has to be red because otherwise you can't get the red underneath it out. That rapidly resolves the ambiguous circles over on the right. Then there isn't enough space to connect the blue parts without going around the top left, which tells you which way the "arms" of the solid red circle near the top left go. The rest is straightforward.

My apologies for the inelegance of my diagram; as you may guess, I drew some things in grey before their colours were resolved.

• I'm afraid you are about a minute late Jul 21 '19 at 14:21
• I don't think so. Your latest solution does something illegal on the left hand edge... Jul 21 '19 at 14:22
• BTW, sorry for the sniping. I started solving before I saw there was someone else attacking it... Jul 21 '19 at 14:27
• I took a different solve path than @GarethMcCaughan. First, consider the solid circle in row 4 column 7. If it had an arm extending to the right, then a little loop chasing fences the portion of the blue loop near row 6, column 9 in the bottom right corner, forcing it to make contact with the red loop near row 9, column 7. The other key step concerns the configuration of the arms emanating from the solid red circle in row 3, column 3 - only one configuration avoids having the red loop cross the blue loop. Jul 21 '19 at 22:03