Kakuro Created 2026-10-20 Updated 2026-11-05
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Kakuro is a numerical cross-sum puzzle on a grid. Each open cell holds a digit from one to nine; every specified horizontal or vertical run must sum to its clue without repeating a digit within that run. It is naturally a constraint satisfaction problem: cells are variables, digits are domains, and each run combines a sum constraint with an all-different constraint. This formulation supports general reasoning about feasible domains and search strategies without selecting or solving a particular puzzle.
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