Backtracking

It's a clever problem-solving strategy that involves exploring possible solutions by building them incrementally, and then, if a solution path doesn't work out, systematically "unbuilding" it to try other paths, like carefully retracing your steps in a maze.

Key characteristics:

• Recursive approach: It often uses recursion to explore different branches of potential solutions.

• Trial and error: It involves trying different possibilities and backtracking if they don't lead to a valid solution.

• Pruning: It can sometimes optimize the search by cutting off branches that clearly won't lead to a solution, saving time and effort.

Common examples:

• Solving Sudoku puzzles: Filling the grid with numbers while satisfying constraints.

• N-Queens problem: Placing N queens on a chessboard so that none attack each other.

• Maze solving: Finding a path from start to finish in a maze.

• Generating permutations and combinations: Producing all possible arrangements of items.

When to consider backtracking:

• Problems that involve finding a combination of choices that satisfy certain constraints.

• Problems where the solution space is large or complex, and you need to explore it systematically.

• Problems where you can easily check if a partial solution is valid or not.