Find Second Smallest Element in an Array (Python)

Understanding Second Smallest Element

Finding the second smallest element in an array involves identifying the smallest element and then searching for the next smallest value.

We will explore three different methods to find the second smallest element in an array using Python.

Method 1: Using Iteration

This method iterates through the array to find the smallest and second smallest elements.

def find_second_smallest(arr):
    smallest, second_smallest = float('inf'), float('inf')
    for num in arr:
        if num < smallest:
            second_smallest = smallest
            smallest = num
        elif num < second_smallest and num != smallest:
            second_smallest = num
    print("Second Smallest Element:", second_smallest)

arr = [10, 20, 4, 45, 99, 23]
find_second_smallest(arr)

Output: Second Smallest Element: 10

Method 2: Using Sorting

This method sorts the array and takes the second element as the second smallest.

def find_second_smallest(arr):
    arr.sort()
    print("Second Smallest Element:", arr[1])

arr = [10, 20, 4, 45, 99, 23]
find_second_smallest(arr)

Output: Second Smallest Element: 10

Method 3: Using Recursion

This method finds the second smallest element using recursion.

def find_second_smallest_recursive(arr, n, smallest, second_smallest):
    if n == 0:
        return smallest, second_smallest
    if arr[n - 1] < smallest:
        second_smallest = smallest
        smallest = arr[n - 1]
    elif arr[n - 1] < second_smallest and arr[n - 1] != smallest:
        second_smallest = arr[n - 1]
    return find_second_smallest_recursive(arr, n - 1, smallest, second_smallest)

arr = [10, 20, 4, 45, 99, 23]
smallest, second_smallest = find_second_smallest_recursive(arr, len(arr), float('inf'), float('inf'))
print("Second Smallest Element:", second_smallest)

Output: Second Smallest Element: 10