Python Program to Find Largest Element in an Array

To find the largest element in an array, iterate over each element and compare it with the current largest element. If an element is greater, update the largest element. At the end of the iteration, the largest element will be found.

Given an array, find the largest element in it.

Input : arr[] = {10, 20, 4}
Output : 20
Input : arr[] = {20, 10, 20, 4, 100}
Output : 100

Find largest element in an array Using Native Approach

Python3

# Python3 program to find maximum
# in arr[] of size n

# python function to find maximum
# in arr[] of size n


def largest(arr, n):

    # Initialize maximum element
    max = arr[0]

    # Traverse array elements from second
    # and compare every element with
    # current max
    for i in range(1, n):
        if arr[i] > max:
            max = arr[i]
    return max


# Driver Code
arr = [10, 324, 45, 90, 9808]
n = len(arr)
Ans = largest(arr, n)
print("Largest in given array ", Ans)

Output

Largest in given array  9808

Time Complexity: O(N)
Auxiliary Space: O(1)

Find largest element in an array Using built-in function max()

Here we will use the inbuilt method max() to find the maximum of the array. Below is the implementation of the approach.

Python3

# Python3 program to find maximum
# in arr[] of size n
def largest(arr, n):
    ans = max(arr)
    return ans;

# Driver code
if __name__ == '__main__':
    arr = [10, 324, 45, 90, 9808]
    n = len(arr)
    print ("Largest in given array ", largest(arr, n))

Output

Largest in given array  9808

Time Complexity: O(n), where n is length of list.
Auxiliary Space: O(1)

Find largest element in an array Using sort() function

Here we use the sort() function to sort the array. The largest element will be the last element of the sorted array. Below is the implementation of the approach.

Python3

# Python3 program to find maximum
# in arr[] of size n

def largest(arr, n):

    # Sort the array
    arr.sort()

    # The last element of the
    # array is the largest element
    return arr[n-1]
    # or return arr[-1]

# Driver Code
arr = [10, 324, 45, 90, 9808]
n = len(arr)
Ans = largest(arr, n)
print("Largest in given array ", Ans)

Output

Largest in given array  9808

Find largest element in an array Using reduce() function

Here we use the reduce() function to iterate over the array. We will find the largest element the max function which will compare each element of array while iterating. 

Below is the implementation of the above approach:

Python3

# Python3 program to find maximum
# in arr[] of size n
from functools import reduce


def largest(arr):

    # Sort the array
    ans = reduce(max, arr)

    return ans
    # or returning largest value


# Driver Code
arr = [10, 324, 45, 90, 9808]
n = len(arr)
Ans = largest(arr)
print("Largest in given array ", Ans)

Output

Largest in given array  9808

Time complexity: O(n) where n is size of given array
Auxiliary space: O(1)

Please refer complete article on Program to find largest element in an array for more details!

Find largest element in an array Using operator.gt()

Create a array of integers and assign it to the variable arr. Print the original array using the print() function.Create an empty array and assign it to the variable arr1.

Sort the original array in descending order using the operator.gt() function and assign the sorted array to the variable arr1. Print the biggest number in the array by accessing the first element of the sorted array using arr1[0]. Print a message indicating that the biggest number in the array has been found.

Python3

# python program to find large number in the given array
import operator
# Initializing the list
arr = [2, 1, 7, 3, 0]
max=0

# printing the original list
print('The given array is:', arr)

#checking for large element
for i in arr:
  if operator.gt(i,max):
    max=i

# printing the large number in the array
print('The biggest number in the given array is:', max)

Output

The given array is: [2, 1, 7, 3, 0]
The biggest number in the given array is: 7

Time Complexity : O(n)

Auxiliary Space : O(1)

Find Largest Element with Python Lambda

In this program, we have an array called array with some elements. We use the max function to find the largest element in the array. The key parameter is set to a lambda function lambda x: x, which simply returns the element itself. This lambda function is used to determine the comparison key for the max function.

Python3

array = [10, 5, 20, 8, 15]

largest_element = max(array, key=lambda x: x)
print("Largest element in the array:", largest_element)

Output:

Largest element in the array: 20