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Program to demonstrate recursive operations

Description​

The code implements a recursive function to calculate the factorial of a number using the concept of repeated multiplication. It takes user input, performs the factorial calculation, and displays the result.

Code​

program9a.py
def fact(n):
    if (n==0 or n==1):
        return 1
    return n * fact(n-1)

n = int(input("Enter the value: "))
res = fact(n)
print("Factorial of",n,"is",res)

Explanation of above code​

fact Function​

  • The fact function calculates the factorial of a given number n recursively. It uses the concept of a recursive function where the factorial of n is defined as the product of n and the factorial of n-1.

Base Case​

  • The base case of the recursive function is defined when n is 0 or 1. In this case, the function returns 1 since the factorial of 0 and 1 is 1.

Recursive Step​

  • For n greater than 1, the function recursively calls itself with the argument n-1 and multiplies it by n. This recursive step continues until the base case is reached.
  • Returning the Result
  • The result of the factorial calculation is returned as the output of the function.

Main Code​

  • In the main code, an integer n is taken as input from the user, representing the value for which the factorial will be calculated.
  • The fact function is called with n as an argument, and the result is assigned to the variable res.
  • Finally, the calculated factorial value is displayed using the print function.
  • This code allows you to calculate the factorial of a given number using a recursive approach. It breaks down the factorial calculation into simpler subproblems until it reaches the base case.

Learn more​

Reference​