Logic Masters Deutschland e.V.

This puzzle is inspired by Build Your Own Killer: Master Designer 2. Traditional X-sum clue is outside the grid, but this is a new trial of inserting X-sum clue into the grid and combining regional X-sum with Chaos-Construction.

Rules:

1. Divide the grid into 9 regions of 9 orthogonally connected cells each. Fill the grid with digits 1-9, such that every row, column and region contains each digit exactly once.

2. No 2x2 area is entirely in a single region.

3. The one-cell cages are X-sum cages, which must appear at the "dead end" of a region. (Only 1 of 4 orthogonal neighbors of the cage cell is in the same region.) The clue number at the top left corner is the sum of the first X orthogonally connected digits in the same region, where X is the digit in the one-cell cage. For cages without number attached, they are still X-sum cages, where the clue number is unknown.

4. The effective range of X-sums must be unique. That means, regions can only branch (T-Shape) out of or at the end of the effective range of X-sums.

5. One region can contain one or multiple X-sum cages.

Example: The X-sum value of the cage-25 is 5+6+1+4+9. The region branches at the 6th cell from the cage-25 so you cannot fill a digit more than 6 in that cell. Note that the restriction above also applies for non-number cages.

Play on CTC