# Python â€“ Check alternate peak elements in List

When it is required to check the alternate peak elements in a list, a function is defined that iterates through the list, the adjacent elements of the array are compared and depending on this, the output is displayed on the console.

## Example

Below is a demonstration of the same

def find_peak(my_array, array_length) :

if (array_length == 1) :
return 0
if (my_array[0] >= my_array[1]) :
return 0
if (my_array[array_length - 1] >= my_array[array_length - 2]) :
return array_length - 1

for i in range(1, array_length - 1) :
if (my_array[i] >= my_array[i - 1] and my_array[i] >= my_array[i + 1]) :
return i

my_list = [ 1, 3, 20, 4, 1, 0 ]
list_length = len(my_list)

print("The list is :")
print(my_list)

print("The result is")
print(find_peak(my_array, array_length))

## Output

The list is :
[1, 3, 20, 4, 1, 0]
The result is
2

## Explanation

• A method named ‘find_peak’ is defined that takes the list and its length as parameters.

• It checks the length of the list and returns result depending on that.

• The adjacent elements of the list are compared and final result is returned.

• Outside the method, a list is defined, and is displayed on the console.

• The length of the list is assigned to a variable.

• The method is called by passing the required parameter.

• The result is displayed on the console.