In the previous article, we have discussed Python Program For Division Two Numbers Operator Without Using Division(/) Operator
Given a list and the task is to find the maximum and minimum elements in a given List using recursion in python
Recursion:
Recursion is the process by which a function calls itself directly or indirectly, and the associated function is known as a recursive function. Certain issues can be addressed fairly easily using a recursive approach. Towers of Hanoi (TOH), Inorder /Preorder/Postorder Tree Traversals, DFS of Graph, and other analogous issues are examples.
Examples:
Example1:
Input:
Given List = [1, 6, 3, 7, 8, 4]
Output:
The Maximum element in a given list [1, 6, 3, 7, 8, 4] = 8 The Minimum element in a given list [1, 6, 3, 7, 8, 4] = 1
Example2:
Input:
Given List = [20, 30, 40, 10, 50]
Output:
The Maximum element in a given list [20, 30, 40, 10, 50] = 50 The Minimum element in a given list [20, 30, 40, 10, 50] = 10
Program to Find Maximum and Minimum Elements in List/Array Using Recursion in Python
Below are the ways to find the maximum and minimum elements in a given List using recursion in python:
Method #1: Using Recursion (Static Input)
Approach:
- Give the list as static input and store it in a variable.
- Calculate the length of the given list and store it in another variable.
- Pass the given list and length of the given list as the arguments to the max_elemnt, min_elemnt functions.
- Create a recursive function to say max_elemnt which takes the given list and length of the given list as the arguments and returns the maximum element in a given list using recursion.
- Check if the length of the given list is 1 using the if conditional statement.
- If the statement is true, then return the first element of the list.
- Return maximum of (gven_lst[len_lst – 1], max_elemnt(gven_lst, len_lst – 1) {Recursive logic}.
- Create a recursive function to say min_elemnt which takes the given list and length of the given list as the arguments and returns the minimum element in a given list using recursion.
- Check if the length of the given list is 1 using the if conditional statement.
- If the statement is true, then return the first element of the list.
- Return minimum of (gven_lst[len_lst-1], min_elemnt(gven_lst, len_lst-1) {Recursive logic}.
- Print the maximum element of the given list.
- Print the minimum element of the given list.
- The Exit of the Program.
Below is the implementation:
# Create a recursive function to say max_elemnt which takes the given list and
# length of the given list as the arguments and returns the maximum element in a
# given list using recursion.
def max_elemnt(gven_lst, len_lst):
# Check if the length of the given list is 1 using the if conditional statement.
if len_lst == 1:
# If the statement is true, then return the first element of the list.
return gven_lst[0]
# Return maximum of (gven_lst[len_lst - 1], max_elemnt(gven_lst, len_lst - 1)
# {Recursive logic}.
return max(gven_lst[len_lst - 1], max_elemnt(gven_lst, len_lst - 1))
# Create a recursive function to say min_elemnt which takes the given list and
# length of the given list as the arguments and returns the minimum element in a
# given list using recursion.
def min_elemnt(gven_lst, len_lst):
# Check if the length of the given list is 1 using the if conditional statement.
if len_lst == 1:
# If the statement is true, then return the first element of the list.
return gven_lst[0]
# Return minimum of (gven_lst[len_lst-1], min_elemnt(gven_lst, len_lst-1)
# {Recursive logic}.
return min(gven_lst[len_lst-1], min_elemnt(gven_lst, len_lst-1))
# Give the list as static input and store it in a variable.
gven_lst = [1, 6, 3, 7, 8, 4]
# Calculate the length of the given list and store it in another variable.
len_lst = len(gven_lst)
# Pass the given list and length of the given list as the arguments to the max_elemnt,
# min_elemnt functions.
# Print the maximum element of the given list.
print("The Maximum element in a given list",
gven_lst, "=", max_elemnt(gven_lst, len_lst))
# Print the minimum element of the given list.
print("The Minimum element in a given list",
gven_lst, "=", min_elemnt(gven_lst, len_lst))
Output:
The Maximum element in a given list [1, 6, 3, 7, 8, 4] = 8 The Minimum element in a given list [1, 6, 3, 7, 8, 4] = 1
Method #2: Using Recursion (User Input)
Approach:
- Give the list as user input using list(),map(),input(),and split() functions.
- Store it in a variable.
- Calculate the length of the given list and store it in another variable.
- Pass the given list and length of the given list as the arguments to the max_elemnt, min_elemnt functions.
- Create a recursive function to say max_elemnt which takes the given list and length of the given list as the arguments and returns the maximum element in a given list using recursion.
- Check if the length of the given list is 1 using the if conditional statement.
- If the statement is true, then return the first element of the list.
- Return maximum of (gven_lst[len_lst – 1], max_elemnt(gven_lst, len_lst – 1) {Recursive logic}.
- Create a recursive function to say min_elemnt which takes the given list and length of the given list as the arguments and returns the minimum element in a given list using recursion.
- Check if the length of the given list is 1 using the if conditional statement.
- If the statement is true, then return the first element of the list.
- Return minimum of (gven_lst[len_lst-1], min_elemnt(gven_lst, len_lst-1) {Recursive logic}.
- Print the maximum element of the given list.
- Print the minimum element of the given list.
- The Exit of the Program.
Below is the implementation:
# Create a recursive function to say max_elemnt which takes the given list and
# length of the given list as the arguments and returns the maximum element in a
# given list using recursion.
def max_elemnt(gven_lst, len_lst):
# Check if the length of the given list is 1 using the if conditional statement.
if len_lst == 1:
# If the statement is true, then return the first element of the list.
return gven_lst[0]
# Return maximum of (gven_lst[len_lst - 1], max_elemnt(gven_lst, len_lst - 1)
# {Recursive logic}.
return max(gven_lst[len_lst - 1], max_elemnt(gven_lst, len_lst - 1))
# Create a recursive function to say min_elemnt which takes the given list and
# length of the given list as the arguments and returns the minimum element in a
# given list using recursion.
def min_elemnt(gven_lst, len_lst):
# Check if the length of the given list is 1 using the if conditional statement.
if len_lst == 1:
# If the statement is true, then return the first element of the list.
return gven_lst[0]
# Return minimum of (gven_lst[len_lst-1], min_elemnt(gven_lst, len_lst-1)
# {Recursive logic}.
return min(gven_lst[len_lst-1], min_elemnt(gven_lst, len_lst-1))
# Give the list as user input using list(),map(),input(),and split() functions.
# Store it in a variable.
gven_lst = list(map(int, input( 'Enter some random List Elements separated by spaces = ').split()))
# Calculate the length of the given list and store it in another variable.
len_lst = len(gven_lst)
# Pass the given list and length of the given list as the arguments to the max_elemnt,
# min_elemnt functions.
# Print the maximum element of the given list.
print("The Maximum element in a given list",
gven_lst, "=", max_elemnt(gven_lst, len_lst))
# Print the minimum element of the given list.
print("The Minimum element in a given list",
gven_lst, "=", min_elemnt(gven_lst, len_lst))
Output:
Enter some random List Elements separated by spaces = 20 30 40 50 10 The Maximum element in a given list [20, 30, 40, 50, 10] = 50 The Minimum element in a given list [20, 30, 40, 50, 10] = 10
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