Recursion and Backtracking in Data Structures and Algorithms (DSA)
Recursion:
Recursion is a programming technique where a function calls itself in order to solve a problem.
It breaks down a problem into smaller subproblems that are identical in structure to the original problem.
A base case is defined to stop the recursion and prevent infinite loops.
Examples of problems solved using recursion include calculating factorial, Fibonacci series, and traversing tree structures.
Backtracking:
Backtracking is a method used to systematically search for a solution to a problem by trying different paths, and when a dead-end is reached, it retraces its steps back to the last valid configuration.
It is often used in problems where there are multiple possible configurations and the goal is to find one or more solutions.
Backtracking typically involves recursive algorithms.
Examples of problems solved using backtracking include the N-Queens problem, Sudoku solving, and solving mazes.
Important Questions and Topics:
Understanding Recursion:
What is recursion?
How does recursion work?
Examples of recursive functions (factorial, Fibonacci, etc.)
Tail recursion vs. non-tail recursion.
Recursion in Data Structures:
Recursion in trees (tree traversal, finding height, etc.)
Recursion in graphs (depth-first search, backtracking algorithms, etc.)