CA 05 - Reverse the array

Problem Statement:

Reverse an array . Reversing an array means the elements such that the element becomes the , the element becomes and so on.

arr[] = [1, 4, 3, 2, 6, 5]

[5, 6, 2, 3, 4, 1]

The first element moves to last position, the second element moves to second-last and so on.

arr[] = [4, 5, 1, 2]

[2, 1, 5, 4]

The first element moves to last position, the second element moves to second last and so on.

Solution:

A brute force method to reverse the given array would be to create a new empty array and append each value from the original array one by one in reverse order using for loop.

Example:

arr= [4, 5, 1, 2]

n=len(arr)

rev_arr=[]

for i in range (n-1,-1,-1):

rev_arr.append(arr[i])

print(rev_arr)

My approach:

My preferred method of solving this problem would be to use the slicing concept. Slicing has the following syntax: array[start: end: step].

Using this we can solve the problem as follows:

arr= [4, 5, 1, 2]

print(arr[::-1])

By using -1 in the step part, we get the array values in reverse.

Output:

[2, 1, 5, 4]