Rules:
1. Place the digits 0-3 twice each in every row and column.
2. Each purple line contains a set of non-repeating consecutive digits, in any order.
3. On green lines, adjacent digits are not consecutive (i.e. differ by at least 2).
4. The grid contains exactly eight "sum cells", one in every row and column. Each digit from 0-3 appears in a sum cell exactly twice. In a sum cell, the digit equals the sum of the digits in the orthogonally adjacent cells.
Solution code: Row 3 (from left to right)
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