Logic Masters Deutschland e.V.

A couple days ago, we intercepted a conversation between 2 officers of the MGC starship, Captain M and Lieutenant C :

- Are you sure this is not on any map, Captain ?
- Affirmative, Lieutenant. An unknown galaxy. We need to inform headquarters. I have here a full map of the area, with the exact position of the stars. But we can’t send this without a proper encryption...
- We have exactly what you need, sir. A brand new star mapping encryption protocol called MEP, for Masyu Encryption Protocol. Very secure.
- Good. Get to work now, high priority. And send the message as soon as you are done.

A few hours later, we intercepted a communication with what we believe is an encrypted map of that new galaxy, with the title : MGC-1326. Your mission is to help us decrypt that message. Figure out the encryption protocol, whatever it is. We need to get our hands on the map of this new galaxy.

Play on Penpa (version with solid grid lines)

Play on Penpa (version with dotted grid lines)

Play on Sudokupad (no answer check)

MaizeGator and I worked on this puzzle together and we are happy to present you the final result of this fun collab. There are a few complex steps in the puzzle, which make the overall experience rather challenging. If you find yourself stuck at some point, do try the example puzzle which contains some ideas that were developed in the main puzzle. And if you are interested, I put in a hidden comment a walkthrough of one of the complex steps in the midsolve.

Rules :

Masyu :
- Draw a non branching non crossing closed loop along the edges of the grid, that must visit all given pearls in the grid.
- Black pearl : the loop must turn on the pearl, and go straight along 2 adjacent cell edges on both sides of the pearl.
- White pearl : the loop must go straight through the pearl, but turn on at least one of the next grid intersection on either side of the pearl.
- Grey pearl : it must behave as a white or a black pearl, to be determined by the solver.

Star battle :
- The Masyu Loop divides the grid in regions of orthogonally connected cells
- Each row, column and region must contain exactly 2 stars. Stars may not touch each other, not even diagonally.

Example puzzle :

Play on Penpa (version with solid grid lines)

Play on Penpa (version with dotted grid lines)

Play on Sudokupad (no answer check)