Tutorial: How to Build a Sudoku Solver in JavaScript Using Backtracking

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A developer tutorial on DEV Community walks through building a Sudoku solver in JavaScript using the backtracking algorithm. The approach works by finding an empty cell, trying numbers one through nine, validating each against Sudoku rules, and recursively filling the board. If a number leads to a dead end, the algorithm erases it and tries the next option — a process known as backtracking. The puzzle is represented as a 9×9 two-dimensional array, with zeros marking empty cells. The tutorial also covers time complexity, noting a worst-case of O(9ⁿ) relative to the number of empty cells, while highlighting that Sudoku constraints significantly reduce invalid paths in practice.

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