Indextra
The brief
- Normal sudoku rules apply, i.e. each row, column, and 3x3 region has to contain the digits from 1 to 9 once each.
- Index Sum Lines: Dots separate turquoise lines into segments which are enumerated with white labels at the center of the line. For each line, the sums of these segments must form a valid Index Line, i.e. the sum value of the Nth segment along the line (starting from the segment with the diamond) indicates the position along the line where a sum value of N appears. For example, if the 3rd segment sums to 6, then the 6th segment must sum to 3.