Recursion Algorithms

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What is Recursion?

The process in which a function calls itself directly or indirectly is called recursion. Using a recursive algorithm, certain problems can be solved quite easily. Examples of such problems are Towers of Hanoi (TOH), Inorder/Preorder/Postorder Tree Traversals, DFS of Graph, etc.

What are Recursion Functions?

Recursive Functions are the corresponding functions that implement Recursion (Function calling itself) within them. A recursive function solves a particular problem by calling a copy of itself and solving smaller subproblems of the original problems. Many more recursive calls can be generated as and when required.

Basics of Recursion Algorithms:

• Introduction to Recursion – Data Structure and Algorithm Tutorials
• What is Recursion?
• Difference between Recursion and Iteration
• Types of Recursions
• Finite and Infinite Recursion with examples
• What is Tail Recursion
• What is Implicit recursion?
• Why is Tail Recursion optimization faster than normal Recursion?
• Recursive Functions
• Difference Between Recursion and Induction

Recursion in different languages:

• Recursion in Python
• Recursion in Java
• Recursion in C#
• How to Understand Recursion in JavaScript?

Standard Problems on Recursion

• Easy Problems on Recursion
  • Print 1 to n without using loops
  • Print N to 1 without loop
  • Mean of Array using Recursion
  • Sum of natural numbers using recursion
  • Decimal to binary number using recursion
  • Sum of array elements using recursion
  • Print reverse of a string using recursion
  • Program for length of a string using recursion
  • Sum of digit of a number using recursion
  • Tail recursion to calculate sum of array elements.
  • Program to print first n Fibonacci Numbers | Set 1
  • Program for factorial of a number
  • Recursive Programs to find Minimum and Maximum elements of array
  • Recursive function to check if a string is palindrome
  • Count Set-bits of number using Recursion
  • Print Fibonacci Series in reverse order using Recursion
  • Coin Change | DP-7
• Medium Problems on Recursion
  • Recursively remove all adjacent duplicates
  • Sort the Queue using Recursion
  • Reversing a queue using recursion
  • Binary to Gray code using recursion
  • Delete a linked list using recursion
  • Product of 2 Numbers using Recursion
  • Programs for Printing Pyramid Patterns using Recursion
  • Length of longest palindromic sub-string : Recursion
  • Program for Tower of Hanoi Algorithm
  • Time Complexity Analysis | Tower Of Hanoi (Recursion)
  • Program to calculate value of nCr using Recursion
  • Find geometric sum of the series using recursion
  • Convert a String to an Integer using Recursion
  • DFS traversal of a Tree
  • Bottom View of a Binary Tree using Recursion
  • Write a program to print all Permutations of given String
  • Print all subsets of a given Set or Array
  • Print all possible paths from top left to bottom right of a mXn matrix
  • Print all combinations of balanced parentheses
  • Longest Common Subsequence (LCS)
• Hard Problems on Recursion
  • Find the value of a number raised to its reverse
  • How to Sort a Stack using Recursion
  • Reverse a Doubly linked list using recursion
  • Given a string, print all possible palindromic partitions
  • Check if a string is a scrambled form of another string
  • Word Break Problem | DP-32
  • Print all palindromic partitions of a string
  • N Queen Problem | Backtracking-3
  • Algorithm to Solve Sudoku | Sudoku Solver
  • The Knight’s tour problem

Practice Sets on Recursion

• Recursive Practice Problems with Solutions
• Practice Questions for Recursion | Set 1
• Practice Questions for Recursion | Set 2
• Practice Questions for Recursion | Set 3
• Practice Questions for Recursion | Set 4
• Practice Questions for Recursion | Set 5
• Practice Questions for Recursion | Set 6
• Practice Questions for Recursion | Set 7
• Practice questions for Linked List and Recursion

Quiz based on Recursion

• Top MCQs on Recursion Algorithm with Answers