Constraint Problems
N-Queens and Sudoku get filed under "hard," but they're the same three-line loop with different rules for what counts as legal. Try a choice, check whether it breaks a constraint, recurse if it holds, undo if it doesn't. The whole game is pruning: catch a violation early and you skip an entire subtree you'd otherwise crawl through cell by cell.
Constraint Satisfaction: You're placing elements or filling values so a set of rules stays satisfied. The moment a partial solution breaks a rule, you abandon it and never look deeper. That early exit is the whole reason backtracking beats brute force here: one failed check can rule out thousands of arrangements you never bother to build.
What's inside
- 1 problem, worked step by step
- about 30 min
Premium lessonData Structures & Algorithms
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