Backtracking is a methodical way of trying out various sequences of decisions until you find one that “works.” It's particularly useful for solving constraint satisfaction problems such as puzzles, combinatorial problems, and optimization problems.

Tips for Backtracking Problems in CP

1. Understand the Problem: Ensure you fully understand the constraints and requirements.
2. Recursive Structure: Identify the recursive structure and base case.
3. Prune Early: Implement pruning to cut off branches that won’t lead to a solution.
4. Memoization: Use memoization to store and reuse results of subproblems.
5. Iterative Improvement: Continuously refine your approach to handle edge cases and optimize performance.

By mastering these techniques, you can effectively tackle a wide range of backtracking problems in competitive programming.

1. Finding All Possible Subsets

2. Subset Sum to Target

3. N-Queens Problem

4. Sudoku Solver