Programming in Python/

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Recursion Types and Limit

Recursion Types and Limit

Learn about the usage of different types of recursion.

We'll cover the following...

Types of recursion

There are two types of recursions:

  • Head recursion
  • Tail recursion

Head recursion

In this type of recursion, the recursive call is made before other processing in the function, as shown below:

Python 3.8
def headprint(n) :
  if n == 0 :
    return
  else :
    headprint(n - 1)
    print(n)
headprint(10)

In the code above, the recursive call happens first, and then the printing takes place. Therefore, the last value of n, i.e., 1, is printed first. So numbers are printed in the order 1 to 10.

Tail recursion

In this type of recursion, the processing is done before the recursive call. The tail recursion is similar to a loop—the function executes all the statements before making the recursive call.

Python 3.8
def tailprint(n) :
  if n == 11 :
    return
  else :
    print(n)
    tailprint(n + 1)
tailprint(1)

In the code above, printing takes place first, and ...