Python Second Max Function

In Python, it is very easy to find the second maximum element in a list. Here we are going to discuss some methods to find the second maximum element in a list.

Method 1: Using Sorted() Function

def find_second_maximum(arr):
    sorted_arr = sorted(arr, reverse=True)
    return sorted_arr[1] if len(sorted_arr) > 1 else None

This method uses the sorted() function to sort the array in descending order and returns the second element of that sorted array. If the array contains only one element, then it returns None.

Method 2: Using max() and Remove() Function

def find_second_maximum(arr):
    max_elem = max(arr)
    arr.remove(max_elem)
    return max(arr) if arr else None

This method first finds the maximum element in the array using the max() function. After that, it removes the maximum element from the array and returns the maximum element again, which is now the second maximum element. If the array is empty after removing the maximum element, then it returns None.

Method 3: Using Looping

def find_second_maximum(arr):
    max_elem = arr[0]
    sec_max = None
    
    for elem in arr[1:]:
        if elem > max_elem:
            sec_max = max_elem
            max_elem = elem
        elif sec_max is None or elem > sec_max:
            sec_max = elem
            
    return sec_max

This method iterates through the array and keeps track of the maximum and second maximum elements. It returns the second maximum element.

Choose the method that suits your code and requirement.