Top 20 Backtracking Algorithm Interview Questions
Last Updated :
21 Feb, 2025
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Backtracking is a powerful algorithmic technique used to solve problems by exploring all possible solutions in a systematic and recursive manner. It is particularly useful for problems that require searching through a vast solution space, such as combinatorial problems, constraint satisfaction problems, and optimization tasks.
In backtracking, we build solutions incrementally, making safe choices at each step. If a choice leads to a dead end (invalid solution), we backtrack to the previous step and try a different path. This method ensures that we efficiently navigate the solution space while avoiding unnecessary computations.
Easy Problems
- Rat in a Maze
- Print all permutations of a given string
- Print palindromic partitions string
- Print all possible paths from top left to bottom right of a mXn matrix
- Subset sum
- Tug of war
Medium Problems
- N Queens Problem
- Word Break Problem
- Find Path from corner cell to middle cell in a maze
- Hamiltonian cycle
- Sudoku
- M Coloring Problem
- Cryptarithmetic puzzle
- Find if there is a path of more than k length from a source
- Partition of a set into k subsets with equal sum
Hard Problems
- Warnsdorff’s Algorithm
- Remove Invalid Parenthesis
- Match a pattern and string using regular expression
- longest possible route in a matrix with hurdles
- Shortest safe route in a path with landmines
Further Practice: Coding Practice on Backtracking