Second largest element from a list/array in python

 

The second largest element of an array in python by creating function

In [1]:

import array as arr

​

def second(A, s):

    m = A[0]

    for i in range(0, s):

        if m > A[i]:

            m = A[i]

    m1 = m

    m2 = m

    for i in range(0, s):

        if A[i] > m1:

            m2 = m1

            m1 = A[i]

        elif A[i] > m2 and m1 != A[i]:

            m2 = A[i]

    return m2

​

A = arr.array('i', [])

​

s = int(input('Enter the size of the array: '))

print ('Enter ', s, ' elements: ')

for i in range(0, s):

    val = int(input())

    A.append(val)

​

if s == 1:

    print ('Only one element is present in the array')

else: 

    res = second(A, s)

    print ('Second largest value of the array is: ', res)

Enter the size of the array: 5
Enter  5  elements: 
10
5
6
5
6
Second largest value of the array is:  6

Finding the second largest by applying the sort() function

In [2]:

li = []

size = int (input('Enter the size of the list: '))

​

print ('Enter ', size, ' elements: ')

for i in range (0, size):

    value = int (input ())

    li.append(value)

li.sort()

li

​

second = li[-2] #Second but not unique

​

for i in range (size, 0): #Making second as the unique value

    if second == li[i]:

        continue

    else:

        second = li[i]

​

print ('Second largest is: ', second)

​

Enter the size of the list: 5
Enter  5  elements: 
8
4
5
5
6
Second largest is:  6